History Main / Synchronization

* In the manga adaptation of ''VideoGame/MegaManX4'', this is the case with Repliforce commander Colonel and his sister Iris, who are Reploid twins. Colonel and his sister Iris were originally created as one Reploid by Repliforce scientists, who wanted to create an ultimate Reploid warrior with a strong fighting spirit and a pacificist heart akin to X. The differences were considered irreconcilable, and they were split into two Reploids. Any damage one sibling receives has similar effects on the other. When Repliforce launches their secession movement for a Reploid-only state and independence from the human government, Zero and Colonel have a fearsome fight, damaging each other and only stopping after Iris interrupts the fight. Iris later faints in Zero's hands because the minor damage that Colonel suffered was still felt by her.
** After Iris is damaged by a computer terminal explosion caused by the deceased Cyber Peacock, Colonel breaks military regulations and goes to the base where she is being treated in a stasis pod to try and save her. He finds Zero and insists on fighting him despite the fact that Zero has already gotten a vaccine for Iris, and tells Zero that it is their desinty to fight. Zero holds nothing back, and slices of Colonel's right arm with his saber. Moments later, Iris's right arm corrodes in the pod. Zero realizes that Iris once said she and Colonel are "two people, one person" and that he is hurting her by damaging Colonel. Despite all this, Colonel refuses to surrender, and charges at Zero one last time. Zero, with an agonizd expression on his face, reluctantly kills him by slicing him in half, [[ShootTheDog knowing full well that doing so would cause Iris to die as well]]. Iris later jolts out of her sleep and breaks out of her pod, and says she feels pain as if there were a hole in her chest. After instinctively going to her brother's corpse, she inadvertently fuses with him and is transformed into a Ride Armor. After she causes some destruction and kills Reploids in the base, Zero smashes the armor and pulls her out of it. Iris tells Zero that even though her brother is dead, she was happy to have spent time with Zero. She then dies moments later because of Colonel's death directly affecting her.
* ''Anime/NeonGenesisEvangelion'': The mecha pilots use neural links to control their Eva units. A meter shows the "synchronization ratio" which depends on several factors including plug depth (increases synch but puts the pilot under more strain as well as risking mental contamination by the Eva) and the pilot's psychological state (being depressed lowers the synch ratio). Low synchronization means you can't pilot the mech at all (it won't even move under 20%), and higher synchronization ratios give the pilot better and better control, but in exchange [[YourMindMakesItReal they feel more of the damage the evas get]]. It's made clear that higher synchronization ratios are dangerous in various ways, but it's not completely explained. Examples:
** On one occasion Asuka was saved by cutting the link a split second before Unit 02 was beheaded by Zeruel's arms.
** When his synchronization ratio exceeded 400%, [[spoiler:Shinji dissolved into his mech and had to be reconstituted. It is said that the same happened to his mother but she didn't come back, as she ''became'' Unit 01's mind and soul.]]
** Similarly, after [[spoiler:descending to a dangerous plug depth in order to save Rei]] in ''Anime/RebuildOfEvangelion 2.22'', [[spoiler:Shinji became trapped in the entry plug for ''[[TimeSkip fourteen years]]'', finally being recovered from Unit 01 in the beginning of ''Evangelion 3.33'']].
** In ''End of Evangelion'', Asuka's ratio reaches 300% and [[YourMindMakesItReal the injuries to Unit 02 are reflected on her body]]. [[spoiler:Seeing that she ran out of power just as she was [[EyeScream speared in the head]] and that her opponents were, for all intents and purposes, [[ImAHumanitarian cannibalistic]] [[AxCrazy harpies]], it isn't necessary to elaborate the result.]]
** It's said that the Eva units' synch rate depends on the pilot's need to "run to mommy". Which is why the units tend to go BERSERK and start acting on their own in moments of extreme turmoil. This is also why, in the original series, Asuka's synch rating actually goes down as she comes to terms with her past with her mother, to the point where she can't even pilot anymore.
* A similar system is used on the [[HumongousMecha Endlaves]] in ''Anime/GuiltyCrown'': pilots are synchronised to their machines via remote interface, though they feel everything the machine does, and Ayase seems to show physical manifestations of damage to her Endlave on her actual body. How a machine is meant to feel pain (and indeed why you'd build in a system which incapacitates your pilots with extreme pain if their machines are destroyed when hot-swapping pilots between machines can be done instantly) is beyond explanation.

* At one point in ''Anime/TheVisionOfEscaflowne'', Van became synchronized to Escaflowne. While this allowed him to win the battle in that episode, it also resulted in him taking serious injuries in the same places the Escaflowne was damaged, and the only way to treat them was to get Escaflowne fixed (with poor Van screaming and [[HeroicBSOD BSODing]] in pain as the gashes were welded closed), since fixing Escaflowne is like fixing any machine, only more complex. And considering that Escaflowne [[PaintItBlack turned black]] when it happened, synchronization could also count as a SuperpoweredEvilSide.
* ''Anime/YuGiOh'':
** In many battles, the duelists seem to be physically weakened by the carnage going on in the card game. In many cases there is some sort of supernatural explanation for this, but it sometimes happens even when no supernatural forces are at play. There is some sort of weak implication that the realism of the holographic systems used causes a stress response in dedicated players -- in one early duel, Yugi's grandfather Sugoroku actually has a heart attack when he loses. Kaiba certainly seems to believe that using his own advanced holographic systems gives him an edge, as his opponents are overwhelmed by the realism of the simulation.
** Yami and Yugi could arguably be this as well, what with the whole [[SharingABody two-souls-sharing-one-body]] business; they're usually in tune with each other's emotions, thoughts and, shown at least once, feel each other's pain. Not to mention that it has been implied that if one of them is killed, the other will die as well.
* In ''Anime/YuGiOhArcV'', Yuya or one of his counterparts entering an [[SuperpoweredEvilSide Awakened state]] will cause any of the others nearby to become Awakened as well, which also leads to them [[SpeakInUnison speaking in unison]].
* In ''Anime/YuGiOhCapsuleMonsters'', it's implied that anyone who loses their only/final Capsule Monster dies. Early episodes show how characters are also harmed when their sole monster suffers damage. When a group of Trents attack and strangle Celtic Guardian, Yami is also choked.
* The Emilys in ''Anime/StrainStrategicArmoredInfantry'' shared a psychic connection first seen when Sara encounters the doll and names it, and the girl takes the name as her own. [[spoiler:The Emily race initially mounted against the Union because they felt their compatriots' pain at being dissected.]]
* ''Anime/RahXephon'':
** This is also implied (but not confirmed outright) to be the case -- in one fight, the [=RahXephon=] is impaled through the shoulder, and Ayato is seen clutching his own shoulder afterwards.
** It's more clearly the case for the people trapped into piloting the enemy Dolems. Ayato himself doesn't quite get this through his head until it's too late, though: [[spoiler: he has already indirectly ''beaten Hiroko to death'' by defeating the Dolem she's linked to.]]
* ''VisualNovel/{{Kanon}}'': Mai and [[spoiler:the demons she fights, due to their actually being manifestations of her own suppressed healing powers]].

* ''Anime/MyOtome'':
** An Otome's Master feels everything his or her Otome does. This was done because in addition to being a prettified bodyguard, an Otome is a WeaponOfMassDestruction. A Master whose life is on the line as well is theoretically less likely to engage in war. Likewise, a Master/Slave Unit in the same series.
** The Slaves that members of Schwarz use follow this principle. If one is damaged, the user is injured, and if one is destroyed, the user dies. The reverse is also true, as a sniper kills a Slave user, and causes the Slave to disappear.

* ''Anime/GunXSword'':
** Van, who [[spoiler:was surgically reconstructed so that]] his life is synched to Dann of Thursday, his Armor. He grows ill if he spends too long without riding it, and if it's seriously damaged he suffers as well. If it's destroyed, he dies. Oddly enough, although no surgery is in his backstory, Ray Lundgren has a similar occurrence -- [[spoiler:when Carossa hurls a giant shuriken into Volcade's eye, Ray's vision goes permanently blurry]].
** [[spoiler:Ray's problem was likely caused by the electric shocks he received when Volkein took damage, or from hitting the back of his head when knocked backwards (which can cause blindness and eye damage).]]
* In ''Manga/FullmetalAlchemist'', when Ed gets severely injured, his younger brother Alphonse blanks out. This is because [[spoiler: Ed and Al are linked, and that Al's body is actually feeding off Ed's--which is part of the reason why he's so short]].
* In ''Manga/CorpsePrincess'', the death of a contracted monk usually leads to the death of his Shikabane Hime. If she goes on living, she is considered just another Shikabane and must be executed.
* In ''VisualNovel/HigurashiWhenTheyCry'', Rika is implied to share this sort of connection with Hanyuu, though it is played for laughs rather than drama, with Rika threatening to eat spicy food whenever Hanyuu fails her. One would assume that either the connection is one-way, or Rika has a much higher pain threshold than Hanyuu [[spoiler:due to all those horrific deaths]].
* In ''Manga/{{Bleach}}'', Captain Komamura's bankai is a giant warrior that mirrors his movements, and any damage inflicted on the bankai will in turn be inflicted on Komamura's body. Since no one else's bankai has this problem, it makes his power in particular a double-edged sword. His typical strategy is to finish his opponent with one blow. The link does, however, come with the advantage of the bankai being able to heal if severely damaged, something no other bankai is capable of.
* ''Manga/OnePiece'':
** Basil Hawkins, a minor character, makes use of [[HollywoodVoodoo voodoo dolls]] that somehow transfer any damage done to him to whatever unlucky sap he managed to make a voodoo doll of.
** Paramecia-types can occasionally have this problem, depending on the power and if it has any transformations. Nico Robin will feel the pain of any attacks against one of her detached, sprouted limbs, and any structural damage suffered by Capone Bege's walking fortress form will be reflected as an injury when he transforms back.
** [[spoiler:Doctor Vegapunk]] somehow manages this between all six of the individuals [[LiteralSplitPersonality he split himself into]]. While this means they all have telepathy with each other, this also extends to ''biology:'' None of the others need to eat, sleep or take care of other biological functions much because they have a single individual doing it all for ''all'' of them.
* Yuka and Mika, twin girls in ''Hot Tails'', share not only each other's pain, but also pleasure. Since ''Hot Tails'' is a {{Hentai}} manga, you can guess how this is applied. To be a tad more specific, Yuka goes out on a date, and Mika, bored and a bit irritated, [[ADateWithRosiePalms entertains herself]]. This makes Yuka's trip to the park with her boyfriend a bit more interesting.

* In ''Manga/BlackGod'', a Tera guardian and a human can form a pact to sync up their "Tera", granting the guardian great strength, though this can be physically tiring to the human partner.

* In ''Anime/EurekaSeven'', Coralians are linked to the Scab Coral. If the Scab is being attacked, all Coralians will feel the pain at the same time, hinting that Eureka will die if the Scab Coral is dead. It becomes an important reason for the protagonists to stop Dewey's plan to annihilate the Scab Coral. This synchronization caused Renton [[spoiler:to lose his beloved Eureka in the manga ending]], while in the movie ending, [[spoiler:Eureka managed to "work around" this fate by becoming fully human(The explanation of how it happened is up to debate, but you can't deny that ThePowerOfLove plays a huge part in this happening).]]
* In ''Anime/RoninWarriors'' (''Yoroiden Samurai Troopers''), the first Dynasty Warrior that Ryo fights causes this effect between himself and Mia (Nasuti) and Yulie (Jun), so if he gets injured, they suffer all of the pain. Ryo eventually defeats him by using his armor's power. (Though how this didn't kill them is not explained.)
* In TheAnimeOfTheGame for ''VideoGame/Persona4'', [[AstralProjection Personas]] act more like [[Manga/JoJosBizarreAdventure Stands]] than in the games. The protagonists do all their fighting through their Personas, and feel any harm that afflicts said Personas.
* ''Manga/FairyTail'':
** Organic Link Magic involves linking two or more things together such that damage to one will result in similar damage done to the other. Laxus' Thunder Palace involves using Lightning Lacrima that, if destroyed, establish a link with the destroyer that causes them to take damage equal to what took out the lacrima alongside getting blasted with the lightning magic already stored inside the lacrima. [[spoiler:Brain's SuperPoweredEvilSide Zero is kept as a SealedEvilInACan via Organic Link magic connecting the six members of the Oracion Seis, with each seal fading as one of the Seis is defeated in battle.]]
** Meldy links Gray and Juvia together via Magulity Sense so she only needs to kill one to kill the other, intending to do so on Juvia by viewing her as the weaker of the two. Despite being burdened by experiencing each other's injuries, Juvia is too tough for Meldy to defeat, so she resorts to linking ''herself'' to them, [[TakingYouWithMe then attempting suicide]]. [[spoiler:Meldy is stopped because the link allows the targets to feel each other's emotions, and [[ThePowerOfLove Juvia's feelings for Gray overwhelm her]].]]
** If one damages an Etherious' Book of Zeref, they harm the Etherious as well. [[spoiler:Zeref uses this to prove that Natsu is E.N.D. during his battle with his brother. Also, if Zeref were to die, Natsu would die too, as the Books of Zeref channel their creator's magic to sustain the Etherious.]] At the same time, any repairs to the Book will also heal them, [[spoiler:as proven when Lucy rewrote the letters that went missing in Natsu's book after Zeref fatally impaled him, which healed the hole in his chest shortly afterwards]].
* In ''Anime/BlackRockShooter'', humans and their Otherselves are linked. When Kagari carves a heart-shaped scar on Yomi Takanashi's chest, the same scar appears on Dead Master. When an Otherself is killed, their human counterpart screams in agony, faints, and then wakes up with no memory of whatever caused them grief and pain. If a human dies, their Otherself ceases to exist (this is never seen, but Saya implies this when she attempts to murder Mato Kuroi to destroy Black★Rock Shooter, but ultimately cannot bring herself to do the deed). As long as the human lives, the Otherself will eventually resurrect.
* ''Anime/MekakucityActors'': It is all but stated in the final episode that this is the case for [[spoiler:Konoha and Haruka (technically owner of the former's body)]], in that if one has his wish granted, the other will disappear/cease to be/die along with him. [[spoiler:One could argue that they are the same person, just split into two parts, but Haruka referring to Konoha as 'the other me' suggests he thinks of him as a separate being]].
* The mechs of ''Anime/DualParallelTroubleAdventure'' are controlled via a pilot's "Life Sympathy", with higher levels being more powerful at the cost of feeling pain when the mech is damaged. Main character Kazuki is the only known male pilot and also has negative Life Sympathy levels that allow him to pull off impossible feats.
* In ''Manga/DragonBall'', when Kami [[EnemyWithout separated his evil side and forced it out of him]], it eventually became [[MadeOfEvil King Piccolo]]. Unfortunately, he went on a rampage and killed thousands of people ForTheEvulz, but Kami couldn't let him die, because if he died, Kami would also die. After Goku mortally wounded King Piccolo, he spat an egg out with his essence that carried on the Synchronization. It eventually hatched into Piccolo Jr, who was linked to Kami just like his father was. Eventually, they fused together again after Piccolo underwent CharacterDevelopment and a HeelFaceTurn.
* The protagonists of ''Anime/{{Kiznaiver}}'', are a group of teenagers bonded together via the "Kizna System" that causes them to feel the pain of the others in an attempt to force them to form a relationship with one another. Initially it is primarily physical pain, but as the series progresses they also feel emotional pain and eventually hear the thoughts of one another.
* ''Manga/FateKaleidLinerPrismaIllya'': When "Chloe" (Kuro Illya) first joins the cast and expresses a desire to kill Illya, Rin and Luvia get around this by carving a magic rune onto Chloe that causes a one-way version of this between her and Illya: whatever pain Illya feels, Chloe will feel too, and if Illya dies, so too will Chloe. This is enough to prevent Chloe from attacking Illya until she undergoes a full HeelFaceTurn, though Chloe keeps the rune for a long time afterward out of sentimentality. They later do the same thing to Bazett to stop her from attacking them. While it convinces her to form a truce, Bazett is so tough that feeling Illya's injuries barely fazes her and she states she could still beat Illya half to death and maintain consciousness afterwards. Unlike Chloe, she found a certain magic-using nun and had the rune removed, though she still kept up the truce.
* ''Manga/AhMyGoddess'': Angels and their host goddesses are linked to each other, and so are doublets, with the Doublet System being the hostage exchange between the gods and the demons in which a young demon and god(dess) link their souls, but then are made to forget whom they're doubletted with (though Welsper and Belldandy would later rediscover their link); killing one kills the other as well.
* ''Franchise/{{Gundam}}'':
** In ''Anime/MobileFighterGGundam'', Gundam Fighters control their Mobile Fighters via the Mobile Trace System, a skin-tight uniform with various receptors on the outfit to control them through movement. Blows to the Gundam translate to blows towards the pilot and severe damage to the Gundam can really harm a pilot as shown when Sai Saici was forced to rip off one of Dragon Gundam's arms to trick the Mermaid Gundam. It's also said that only the best pilots can handle the suit as those unsuited for it can be injured or killed.
** In ''Anime/GundamBuildFightersTry'', Sekai develops a strange ability known as "Assimilation" that allows him to link up (in an undefined way) with his Try Burning Gundam Gunpla, making it stronger, though damage done to the Gunpla translates to injuries onto him.
* ''Manga/AyakashiTriangle'':
** Suzu can [[SelfDuplication create a duplicate]] of herself called an omokage, which she shares senses with, including pain. It was initially speculated the injuries would also transfer over, but it was later shown the omokage being torn to pieces only make Suzu feel the pain.
** Sosuke's Engulfing Shadow is a giant spectral mouth that he can eat LifeEnergy through, but damaging it will also damage his actual mouth or more.
** The [[GenderBender sex-changing]] {{curse}} that Shirogane put on Matsuri links them together in special circumstances, even after Shirogane became too weak to remove it. When Shirogane had a bad cold, Matsuri's could feel the mark it left burning to the point he collapsed. One failed attempt to remove the spell instead caused Shirogane to start FadingAway. Shirogane has claimed killing him would make the spell irreversible.

* Old Lace, the psychic velociraptor, in ''ComicBook/{{Runaways}}'', with her owner Gertrude [[spoiler:and later Chase]].

* ''Franchise/{{Transformers}}''
** In ''ComicBook/TheTransformersLastStandOfTheWreckers'', Topspin and Twin Twist have "vicarious preception" (basically a fancy name for this trope). [[spoiler:Eventually, Twin Twist ends up being tortured by Decepticons, and the other Wreckers are at a computer where the password-bypass system is for someone to sacrifice themselves. Topspin decides, knowing that his brother is in serious pain anyway, to [[HeroicSacrifice offer himself to the computer]].]]
** In the original Marvel Comics [[ComicBook/TheTransformersMarvel Transformers]] series, Megatron and Ratchet ended up fused together after a freak accident. They were seperated, but Ratchet wound up seeing (and feeling) what Megatron did.
** Returns in a horrible way in the ''Regeneration One'' comic series, a continuation from where the US Marvel line left off after issue 80. [[spoiler: [[TheBusCameBack Megatron's back]] after [[NoOneCouldHaveSurvivedThat surviving the crash of the Ark off-panel]]. By extention, so is [[TheMedic Ratchet]]. However, Ratchet is [[AndIMustScream confined to a tortuous existence]] a [[LosingYourHead living head mounted on the front of Megatron's battle sled]], forcing Ratchet to watch as Megatron lays waste and [[{{Necromancer}} reanimates dead Transformers]] as zombies.]]
** Also in the Marvel series, Pretenders felt everything their Pretender shells felt regardless of whether or not they were wearing them at the time. At least one Pretender was killed by the pain he experienced from having his shell destroyed when he wasn't in it.

* In ''ComicBook/TheSmurfs'' comic book story "The Hundredth Smurf" (and its AnimatedAdaptation), Vanity had synchronized movements with his mirror duplicate until the duplicate got knocked out by running into a wall (or, in the case of the cartoon show, until the duplicate fell down the stairs and out the door of Vanity's house).
* In ''ComicBook/MyLittlePonyFriendshipIsMagicIDW'', when the portal to the MirrorUniverse is open, the inhabitants to both worlds are linked, leading to a scene where the evil Celestia sadistically attacks the evil Luna just to injure the good Luna.
* Khaal and his brothers in ''ComicBook/KhaalTheChroniclesOfAGalacticEmperor'' have their lifeforce tied together as result of being {{half human hybrid}}s born from a [[GreenSkinnedSpaceBabe female Psycog]]. If one of them dies, the other two will follow them. Khaal discovers this when he nearly murders his brothers in a fit of madness, but their dying father stops him with this revelation. At the end, [[spoiler:as part of [[TheBadGuyWins his victory]], Khaal traps his brothers in [[AFateWorseThanDeath a blob-like prison]] ala ''Literature/IHaveNoMouthAndIMustScream'', ensuring that they never die and cause his own death]].

* An underground comic called ''Clio's Problem'' had this on a grand scale. The narrator is visiting her old friend Clio who she hasn't seen in years, and has definitely seen better days. Especially since she seems to be suffering from a delusion that every time something bad happens to her, something worse happens to the world. She gets in a fender-bender, there's a twenty-car pile-up. She burns herself on a stove, an apartment building burns down with everyone inside. Even mental problems have consequences, from her anorexia causing a famine to her depression causing a wave of suicides. She has pages and pages of evidence and even demonstrates the curse by stabbing herself with a needle...causing a news report to come on about a famous actor who just got randomly stabbed to death. Her friend still thinks it's all coincidence, and that's when Clio drops the bombshell...she has AIDS. She has maybe six months left and is terrified of what will happen to the world when she dies. Her friend still doesn't believe it's real, and then an angry Clio suddenly slips on the floor and knocks herself out...and as soon as she falls unconscious, the city is hit with a blackout. The last panel is Clio's friend with a look of dawning horror on her face.

* In chapter 11 of [[https://www.fanfiction.net/s/4588115/1/The-Wind-Waker The Wind Waker]], Link fights two Bokoblins and a Moblin at the top of Dragon Roost Island to free Medli from a prison cell, like the game it's based on. Unlike the game, the three monsters are linked by magic. When Link slays the Moblin, the Bokoblins drop dead as well.
-->'''Medli:''' I see. The Bokoblins and the Moblin were magically linked. You kill the Moblin and all three die.
* In the final chapters of the Music/{{Vocaloid}} fic ''Fanfic/RottingCamellias'', Miku finds a way to [[spoiler: use this trope against Meiko, who has been keeping her locked in a cage.]]
* In the ''Fanfic/FacingTheFutureSeries'', [[spoiler:Danny and Sam develop a link that allows them to sense how the other is feeling and where each other are, right down to the last step they are making]].
* ''Fanfic/AChanceMeetingOfTwoMoons'': Alternate universe counterparts can develop this; in Artemis and Luna's case, it ultimately leads to [[spoiler:a full-blown PsychicLink, letting them speak telepathically to one another even from different worlds]].

* ''[[https://archiveofourown.org/works/19395253 Pain]]'' is an ''Series/{{Arrow}}'' SoulmateAUFic where soulmates feel each other's pain, physical and emotional. Deconstructed, in that that turns out to be exactly as horrifying as it sounds. Sara has a JerkassRealization upon learning Oliver didn't feel her pain (and thus she slept with her sister's boyfriend for nothing); and Oliver has one when he realizes the near constant sense of heartache and betrayal might be coming from Laurel, making him realize just how badly he hurt her. Laurel meanwhile is forced to drop out of law school, and can't even hold a regular job, as she keeps feeling his pain of combat, torture, etc.

* Prince Nuada and his sister Princess Nuala suffer from this in ''Film/HellboyIITheGoldenArmy''. This ends in [[spoiler:Nuala performing a HeroicSacrifice by killing herself in order to stop her brother's plans]]. It also makes the HostageForMacGuffin ultimatum the villain makes with his sister as the hostage rather stupid. And Abe even [[IdiotBall stupider]] for doing it anyway.

* ''Creator/CheechAndChong's The Corsican Brothers'' plays the classic tale for laughs.
* In ''Film/{{Pumpkinhead}}'', those who summon the eponymous vengeance demon feel the pain that the demon causes to its victims, and Pumpkinhead feels the pain caused to its summoner; the only way to kill Pumpkinhead, therefore, is to kill the summoner.
* ''Film/ETTheExtraTerrestrial'': E.T. and Elliot share a psychic bond. As Michael puts it, "Elliot feels [E.T.]'s feelings."
* In ''Film/TheCarpenter'', the ghostly carpenter is pained whenever his house is damaged. He's vanquished when the place is set on fire, which causes him to burst into flames.
* Part this, part MentalFusion is required on the behalf of the pilots in ''Film/PacificRim'' so that they can control the powerful [[HumongousMecha Jaegers]] with a neural link. More than one pilot is necessary to take the mental strain of moving a giant robot with your mind, so Jaeger pilots must be "Drift-compatible" in order to ensure that they can work together effectively. To facilitate this, most (though not all) pilot pairs are family members or romantic couples.

* In ''Film/{{Dragonheart}}'', when a dragon shares half his heart with a human, they share each other's pain, and the human's life is also linked to the dragon's: as long as the dragon lives, so does the human; if the dragon dies, the human does too.
* In ''Film/AvengersAgeOfUltron'', {{twin|Telepathy}}s Quicksilver and Scarlet Witch are linked this way (at least, Scarlet Witch, as TheEmpath, feels what Quicksilver feels. It's never mentioned whether the link goes both ways). When [[spoiler:Quicksilver dies]], it doesn't do the same to Scarlet Witch, though judging from the way she screams when it happens, it is pretty bad for her, too.
* In ''Franchise/StarWars'' continuity, the Tusken Raiders of Tattoine ride giant, shaggy beasts called banthas, which share a near-supernatural bond with their owners via a combination of training and affinity. A bantha is always the same gender as its rider, and when two Raiders marry, their bantha's also become mates. If a bantha's rider dies, the bantha usually dies shortly after, often becoming feral and violent before dying.
* ''Film/TheSuicideSquad'': Starro's {{Puppeteer Parasite}}s are an extension of him, so when his giant {{Kaiju}} form gives a MightyRoar, everyone taken over by him mimics it, and when Polka-Dot Man slices a limb off, they [[HurtFootHop stand on one leg and clutch the other]] while screaming in agony.

* In ''Film/MagicInTheWater'', the lake monster Orky briefly possesses a number of people, leaving all of them with a link to him. They all develop a rash and eventually fall ill due to [[spoiler:toxic pollution making Orky sick]].

* ''Series/TheRiseOfPhoenixes'': Ning Yi and his father are linked, so his father feels ill when Ning Yi does. This is how the emperor knows when [[spoiler: Ning Yi is just pretending to be unwell.]]
* ''Series/LostLoveInTimes'': Qing Chen links her life with Yuan Ling's to stop him killing her. When she cuts her finger, his finger starts bleeding too. When he's poisoned, the poison affects her too.

* In ''Series/{{Fringe}}'' a boy becomes synchronized with a fungus. If it dies, he dies, and he senses what it senses (light, heat).

* In the ''Series/RedDwarf'' episode [[Recap/RedDwarfSeasonIVJustice "Justice"]], the Justice Field reflects any criminal acts back upon the actor. If you try to light the sheets on fire, you end up lighting yourself on fire (and the sheets stay unburnt). "It's the ultimate deterrent," as Rimmer says. This situation leads to a marvelous fight in which hitting your opponent hurts ''you'' instead. The bad guy, a Simulant (think the Terminator with ''really'' bad BO) [[TooDumbToLive is too dumb to realize what's going on]]. So he tries shooting Lister and throwing a knife at him. Twice. Lister even draws a target on his groin and presents it for kicking. Then he hands the Simulant a few giant vases, to be smashed over Lister's head. The Simulant then tries to strangle Lister, thus strangling himself. With the bad guy defeated, [[{{Cloudcuckoolander}} The Cat]] turns up, armed with a spade...

* In one episode of ''Series/StarTrekTheNextGeneration'', Capt. Picard and Dr. Crusher are (slowly) synchronized by alien technology implanted into their brains as a prisoner control device (they experience debilitating pain and nausea if separated too far). Slowly because the implants gradually get more effective as they "learn" their hosts' brains. Mostly, though, the whole episode is an excuse to get them to talk to each other about their feelings.
* On ''Series/StarTrekDiscovery'', Michael Burnham was killed in a terrorist bombing when she was a child, and she only came back to life because Sarek used a mind-meld to transfer a piece of his ''katra'' to her. As a result, they share a telepathic link; when Sarek is later injured by a suicide bomber, Burnham collapses in pain.
* ''Series/LegendOfTheSeeker'': The maternity spell Nicci uses to hold Kahlan hostage.
* In ''Series/TheVampireDiaries'' [[spoiler:Katherine has a witch create synchronization between herself and Elena to prevent the Salvatores from killing her. They end up stabbing Katherine non-fatally a couple times before being informed about what's happening to Elena.]]
* Multiple artifacts in ''Series/{{Warehouse 13}}'' have this kind of effect. Most notably, [[spoiler: Johannes Maelzel's metronome]], which can bring someone back to life, but causes the person who brought them back to feel any pain they feel.

* In ''Series/HerculesTheLegendaryJourneys'', if a person dies or is injured, their MirrorUniverse counterpart will suffer the same fate and vice-versa. [[spoiler: However, if a person is in the void between worlds, only pain will transfer, as shown when The Sovereign is killed, Hercules feels the pain of being stabbed, but survives.]]
* One of the comedy skits from ''Series/TheElectricCompany1971'' had the Corsican brothers inflicting pain on themselves so that the other would feel until the both of them collapsed.
* ''Series/{{Charmed|1998}}'':
** In one episode, Phoebe synchronizes with a MagicalNativeAmerican man who was trapped in a time loop in an alternate dimension and sentenced to die, something that would kill Phoebe as well.
** Most of the TimeTravel episodes had characters (most notably [[spoiler: Chris and Wyatt]]) synchronized to their past-selves so that anything that happened to the past character happened to the time traveler as well.
* In ''Series/{{Haven}}'', the villain William is linked to Audrey, which makes it rather difficult to fight him. On the plus side, he has a HealingFactor, and when he heals, Audrey does as well. At one point, Nathan resorts to knocking her out to defeat him. There is also an amusing scene where Nathan hits him with a GroinAttack, and it ''doesn't'' hurt her. It seems to only apply when they are in the same world; they defeat him by throwing him through a portal to another world without any concern for what happens to him.

* In ''Series/BabylonFive'' when Lochley and Zack go to arrest Lyta in Season 5 she demonstrates her TouchedByVorlons powers by drumming her fingers on a table, followed by everyone else in the zocalo doing the exact same thing.
* ''Series/MechX4''. Ryan Walker is bonded to the eponymous robot, so whatever damage is done to the robot also hurts him.
* One episode of ''Series/{{Bewitched}}'' had Endora casting a spell to synchronize Samantha and Serena.
* ''Series/BlakesSeven''
** "Death Watch" has the in-universe audience synchronised to one of two dueling champions so they can experience his emotions during the DeadlyGame. This is not just for vicarious thrills but because the CombatByChampion is their substitute for warfare, so it's regarded as entirely proper that the general population experience these feelings as well.
** In "Voice From the Past", the crew try to cure Blake from his brainwashing by linking their minds to his. When Blake goes berserk Avon tries to knock him unconscious, only for Jenna (who's mindlinked to him at the time) to feel the blows as well.
* ''Series/OnceUponATime'': People split by Dr. Jekyll's newest serum have this, but it works somewhat oddly. Hyde dies when Jekyll is fatally impaled, yet when Regina splits the Evil Queen off and crushes her heart, the Evil Queen revives shortly afterward. The only way to permanently kill her is to do so after their link is severed by the Shears of the Fates. (Not that she ''does'' get killed, since Regina develops a new plan that works out for the better.)
* ''Series/UltramanAce'': This effect happens to humans who sold their souls to the demon-lord, Yapool, for Choju possession, where their souls will be connected to the monster they summoned. A notable example with the first of it's type: the monster Garan is born from a MadArtist, Kuri, selling his soul to bring artworks depicting his monster into the human world, and Kuri is able to control Garan by synching the monster's movements by sketching it on a drawing panel, but in the penultimate battle when Ultraman Ace managed to sever one of Garan's limbs, Kuri the artist feels his monster's pain as well and is forced to drop his paintbrush and collapse holding his arm.
* ''Series/MotherlandFortSalem'':
** {{Played with}}, as Raelle has a magical link to Scylla that allows Scylla to transmit messages to her via their palms. They don't share sensations otherwise.
** Alder and her biddies are somehow linked by magic. Thus, when Alder suffers an attempt on her life, the injuries are shared between them, sparing all their lives.
** [[spoiler:Petra Bellweather]] innocently taps her pen on her desk, but actually syncs an enemy officer's heartbeat to the tapping. The faster she taps, the higher his heart rate. She continues until his heart gives out and he drops dead.
* ''Series/TheWheelOfTime'': Aes Sedai and Warders share a bond which results in one's condition affecting the other. For example, when an Aes Sedai falls unconscious it weakens her Warder. When Lan drinks alcohol, Moiraine becomes [[NotSoStoic noticeably emotional]]. At [[spoiler:Stepin's funeral]] as Lan grieves his dead friend Moiraine starts to cry as well.
* ''Series/TheOrder'': Binding spells involve people sharing blood by cutting their palms and clasping them while they say an incantation. After this any harm that comes to one is shared with the other. This is used to keep trust and hold hostages.

* [[https://www.youtube.com/watch?v=GMMGkwGEJlY The Figurehead]] by The Merry Wives of Windsor is about a foolish captain who dearly loves both his ship and his [[WomenAreWiser much wiser bride]], and so elects to have his ship's figurehead fashioned in her likeness. On the ship's next voyage out she gets a deep cut on her arm just as the ship gets damaged by a coral reef, and on the voyage after that she breaks her leg just as the ship's mizzenmast is destroyed in a storm. Realizing what's going on and worried that it might actually kill her if she doesn't put a stop to it, she uses her link to the ship to destroy it before it kills her, dooming her husband and his crew in the process.

* ''TabletopGame/Warhammer40000'':
** [[HumongousMecha Titan]] Princepes suffer physical pain when their titans suffer battle damage. Not merely the Princeps, but the key members of his crew also suffer such pain, in varying degrees, particularly the Moderati.
** In a similar manner to the above, [[MiniMecha Tau Battlesuit]] pilots suffer from this, including "battlesuit psychosis", in which they are so linked to the suit, so used to it that they cannot function without the suit's sensors as filters for their own senses, and if the suit is damaged, (say by the loss of an arm), the pilot will find themselves unable to use that arm until the suit is repaired. The Tau also have a [[BloodBrothers 'bonding ceremony']] which, [[TrueCompanions while largely symbolic]], has been known to have the occasional extreme side effect, to the extent that the death of a member of the bonded team can drive the survivors insane (by Tau standards).

* In ''Tabletopgame/BattleTech'', pilots wear neurohelmets which link their consciousness to their Mechs and lets the [[HumongousMecha BattleMech]] use the pilot's sense of balance to keep upright. It also functions as a security system, to prevent other pilots from stealing a Mech. The link is explicitly and wisely not two-way in most occasions, but "neurofeedback" can result from ammunition explosions. It is described as extremely painful, and frequently renders the pilot unconscious from sensory overload. If it happens too much in a short time, it can even kill the pilot, similar to how a strong shock across the heart can stop it.

* In the ''VideoGame/MegaManBattleNetwork'' series, Lan and his Net Navi [=MegaMan.EXE=] often synchronize with each other.
** A particularly extreme example occurs at the end of ''Battle Network 3'', when Lan [[spoiler: digitizes himself into the net world and literally fuses with [=MegaMan.EXE=] in order to increase the latter's power as much as possible to destroy the BigBad Alpha.]]
** From ''Battle Network 4'' onwards, it becomes a true gameplay effect: Damaging enemies just before they attack causes this, which gives you double damage on your next attack. It's even more extreme in the manga, where the consciousness of the Operator and Navi actually merge. In addition, any damage done to the Navi in the virtual world is transferred to the operator, be it a small cut, a dismembered limb, or full-out deletion/death. The concept in general is taken a bit further than usual, with Full Synchro being explained as [[TechnoBabble eliminating the delay between a command being issued and its execution]], which is absolutely necessary to the most powerful of the autonomously operating Net Navis, who don't have such a delay in the first place.

* In ''VideoGame/FinalFantasyIV'', Cecil and Kain murder Rydia's mother by killing her conjured dragon. In the DS remake, Pochika/Whyt is a substitute for the party Summoner, and is thus bound by the same rules. If it dies, she does as well.
* ''VideoGame/BloodlineChampions'' has the Psychopomp's Soul Link ability, damaging and causing an effect on enemies hit to also cause their allies hit by the effect to take an additional 20% of the damage they personally take while the effect is on. The Guardian had an ability called Thrust, which would cause an ally you hit to have part of the damage they take while affected be done to the Guardian, with the damage the Guardian taking from that being also reduced.

* ''VideoGame/TheWorldEndsWithYou'':
** The characters ''have'' to synchronize themselves with another player, if they want to win the game. This, however, comes with all of the above explained consequences. This works the same way during battles, as enemies and Players alike share life force on the top and bottom screens. If Neku defeats an enemy on the bottom screen, it is also [[DeadlyEuphemism erased]] on his partner's side.
** In addition, eating food raises the Sync Ratio of your partner (somehow?). The lower the Sync Ratio, the less effective they are in battle, with a 0% sync resulting in insultingly bad performance. Yeah, the more they like the food, the better; they gives audio cues as to how each food item appeals to them. But this is a temporary effect, fading within a few battles; for increased sync that lasts longer, Neku and partner should really wear the same brands.
* The final boss in ''VideoGame/PlanescapeTorment'' is [[spoiler:The Transcendent One, the Mortality of the Nameless One]]. Both it and the protagonist are immortal [[spoiler:due to being separated magically]] and one way to end the game is to [[spoiler:use a weapon that can permanently kill the Nameless One, the Blade of the Immortal, on yourself; this will destroy both of them.]]

* Rynn and Arokh make a "Bond" in ''VideoGame/{{Drakan}}: Order of the Flame'' that effectively synchs their hit points with each other (in-game it is described as "merging their existences into one"). It doesn't seem like a fair trade at first, since Rynn is a mere mortal and Arokh is a [[OurDragonsAreDifferent nigh-unstoppable dragon]] but apparently, only killing Arokh kills Rynns as well, not vice versa. This is also supported by the fact that the human who originally made a Bond with Arokh (a certain Heron) has been dead for centuries when Rynn meets Arokh.

* The InteractiveFiction game ''VideoGame/SavoirFaire'' has a magic system based around linking objects so that what happens to one happens to the other as well. People can also be linked, and it's said that members of feuding aristocratic families are often linked to one another as a sort of hostage thing, so that one family can't harm members of the other without also hurting their own relatives.
* ''VideoGame/BioShock2'' reveals that the first series of Big Daddy would fall into a coma and die if their Little Sister were killed. Or if they just wandered off too far.
** Sofia Lamb actually exploits this, [[spoiler:by smothering (but not killing) Eleanor in front of Delta, fatally injuring the bond between them. The broken bond ends up being one of the contributing factors in Delta's death.]]
* In ''Videogame/KidIcarusUprising'', Dark Pit is connected to Pit, since he's really the physical manifestation of Pit's "dark side" (not that Dark Pit is actually dark - more neutral than anything). Their level of synchronization is actually very vague -- battle damage to one Pit does absolutely nothing to the other, but when Pit [[spoiler:gets trapped in a ring]] for three years, Dark Pit is unconscious the whole time. Thus the latter realizes that he's connected to Pit, [[CloningBlues much as he dislikes it]].
* The Life Link concept in ''VideoGame/BlazBlue''. What makes it unique is that so long as one lives, the other will continue to survive and the only way to kill them is to take out both individuals at the same time. Ragna/Nu-13 and Terumi/Mu-12 are known examples of this.
* In ''Videogame/Dishonored2'', Emily has the Domino ability, which allows her to link multiple people together so that dispatching one will take out the others. She can even summon a Doppelganger to be used as a target.
* In ''VideoGame/GranblueFantasy'', the player character is character is mortally wounded early on, forcing [[MysteriousWaif Lyria]] to use her powers to save them. This links the pair's lives together, which is what kicks off their travels together. In gameplay, Lyria normally isn't a party member, but she's responsible for your SummonMagic, so if the player character is knocked out, you're locked out of your summons as well. An anniversary event gave her a playable version, and if either you or Lyria are knocked out while she's in the party, then the other is knocked out as well.
* Comes up in both ''VideoGame/NiNoKuni'' and ''VideoGame/NiNoKuniIIRevenantKingdom''. In each world, there is someone who shares the same soul as the other. Something that happens to one will happen to the other. Usually the same soul cannot exist in the same world twice, so usually travel is impossible. This is a major plot point in both games.
* ''VideoGame/XenobladeChronicles2'':

* In ''VisualNovel/{{Tsukihime}}'', the maids Hisui and Kohaku are known as Synchronizers. It is known they can give other people energy and maintain their sanity [[spoiler: or remove it little by little...]] Also Shiki and SHIKI in Hisui's route connect during dreams and feel the pain/take the damage of the other. Unfortunately, SHIKI has something of a HealingFactor...

* ''VisualNovel/FateHollowAtaraxia'': Avenger's Noble Phantasm, Verg Avesta, causes a one way version of this. Any pain or injuries Avenger takes reflect on his opponent. The ability is rather impractical however. It only affects one opponent at a time, and he has to concentrate to use it, so if an attack knocks him unconscious or kills him, he out of luck. And since he's physically frail, he's likely to be incapacitated by injuries long before his opponents.

* Two of the main characters of ''Webcomic/{{Darken}}'', Gort and Mink, share such a bond. Mink is rather annoyed by it, due to Gort's tendency to [[LeeroyJenkins charge into trouble]] with his sword raised, often commenting "He's going to get us BOTH killed!" Gort was the one who agreed to the creation of this link, in order to [[PetTheDog save Mink's life]], and nobody's entirely sure why (since he's basically a supervillain), though allegations of a romantic relationship between the two HAVE been made.

* Happens both ways in ''Webcomic/TheDragonDoctors.'' When Kili's soul is plunged into darkness and imminent death by an evil spirit, her empathically-bonded lover Greg nearly dies along with her, but is able to use his connection to save her and himself.
* ''Webcomic/StandStillStaySilent'': One is implied between Lalli and Tuuri when [[spoiler:Tuuri drowning briefly causes Lalli's chest to hurt bad enough for him to lose his balance off his seat]].

* ''Webcomic/BowsetteSaga'': According to Chompy, Chain Chomps feel any damage their chain takes, a precaution that prevents them from biting through them. Chompy is willing to take the pain when she bites through her chain so she can help Bowsette, getting a power boost in the process.

* Appears to be what is happening to the six main characters of [[https://sixchances.com/ Six Chances]] who become connected with one another through a PsychicLink. If one of them is gravely injured, they all feel it. And if one of them dies... Well, they haven't dared to try it out.

* Demona and Macbeth from ''WesternAnimation/{{Gargoyles}}'' were synchronized by a magic spell that caused them to feel each other's pain whenever they are in close proximity, implied to be intended to keep Demona loyal as Macbeth's protector. Since they came to hate each other's guts, there has been a series of violent confrontations where they're essentially beating ''themselves'' up by fighting the other. This is the source of their immortality compact, handed out by the mystical tricksters that granted the wish; they cannot die [[OnlyICanKillHim unless one kills the other]], at which point ''both'' will. It's seemingly Macbeth's [[DeathSeeker life goal to do just that.]]
* Tomax and Xamot from ''Franchise/GIJoe'' are an example of synchronized twins. It seems to end at pain (and possibly pleasure), though -- Xamot has a facial scar that Tomax lacks.
* Referenced on ''WesternAnimation/FamilyGuy'' when Stewie and Brian pretend to be them.
-->'''Stewie:''' I'm Tomax and this is Xamot. We're twins who can feel each other's pain.\\
'''Brian:''' ''[after Stewie steps on his foot]'' Ow!\\
'''Stewie:''' No Brian, I'm supposed to say 'ow!' You ruin everything!\\
'''Brian:''' ''[after punching Stewie]'' Ow.

* The subject of the ''WesternAnimation/MenInBlack'' episode "The Psychic Link Syndrome".
* ''WesternAnimation/{{Wakfu}}'': Amalia (like any Sadida) is somewhat synchronized with her animated puppet, which she uses to fight (though this doesn't transmit wounds; in fact she can use it as a shield). This turns out quite problematic in episode 7, where Amalia gets poisoned and thus delirious, and the puppet becomes a nasty, evil little pest.

* In ''WesternAnimation/TransformersPrime'', Starscream makes an army of clones, only to find out that he feels whatever pain they experience. He discovers this when Bulkhead ''beats one to death''. Luckily he only feels the pain and doesn't receive any actual damage, else he wouldn't have survived Megatron killing three more in short order, [[spoiler:and he himself murdering the last [[TheStarscream treacherous]] clone by first blowing a hole through its chest, and then blasting it in the head [[ScreamDiscretionShot as the episode fades to black, capped off with him screaming about how much it hurts]]]].
-->'''Starscream:''' My genetic code provides my clones with [[ShapeshifterModeLock a T-Cog that I no longer possess]], and all I get is their agony?!

* ''WesternAnimation/{{Centaurworld}}'': [[spoiler:This turns out to be the case with the General and the Nowhere King, because they're two halves of one being, an elktaur which magically split himself into human and deer halves (with the deer half later mutating into the Nowhere King's skeletal form). Horse realizes this means the General will never bring their war with the Nowhere King to an end because killing the Nowhere King will kill him too.]]

* ''Wiki/SCPFoundation'', [[http://www.scp-wiki.net/scp-607 SCP-607 ("Dorian")]]. When SCP-607 bonds with someone, anything that happens to it (physical or emotional) will also happen to that person. It also happens to be [[DrivenToSuicide suicidal]], which means anyone it bonds with will not last much longer.

* In the ''WesternAnimation/JackieChanAdventures'' fanfic ''Fanfic/TheUltimateEvil'', it would seem that two people who are [[WonderTwinPowers Others]] to each other can feel each other's pain in extremely painful situations. Most often it happens between Shendu and Valerie, like when Shendu is rendered unconscious for being in touch with the [[KryptoniteFactor Pan'Ku Box]] and Valerie is blasted in the face with [[PlayingWithFire the Dragon Talisman]].

* ''WesternAnimation/CaptainPlanetAndThePlaneteers'': Captain Planet is synchronized with Gaia (whenever she's hurt, his powers fail). Gaia is linked to the Planeteers (if they turn on her or abandon her, she loses her powers). And of course the whole team is connected through Ma-Ti, and Gaia is synchronized with the whole Earth... oh... as they say on ''WesternAnimation/AvatarTheLastAirbender'', everything is connected. Example: When Gaia temporarily lost her powers, Captain Planet was depowered and couldn't dissipate, meaning that the Planeteers rings didn't work.

->'''Xamot:''' ''(grunts in pain)''\\

'''Alpine:''' Terrific! Pass ''this'' on! ''(punch)''

-->"She is?" Celestia asked, and she groaned when Bean nodded. "Ugh. She better not complain about it then."\\

"No so much that. She—"\\

"That—" Celestia said with a longsuffering sigh "—is what I meant."\\

"You are hereby prohibited from ever getting sick again." Luna announced, as she checked her other wing for any open flames. "And are you completely sure there is no way to turn down the temperature on that thing?"

* Played for comedy in Creator/StephenChow's ''Film/RoyalTramp''. When Stephen finds out they're synchronized, he insists on "testing" them, taking one behind a curtain and leaving the viewer to figure out what he's doing by the reactions of the other one.

* In the movie ''Film/{{Pumpkinhead}}'', those who summon the eponymous vengeance demon feel the pain that the demon causes to its victims, and Pumpkinhead feels the pain caused to its summoner; the only way to kill Pumpkinhead, therefore, is to kill the summoner.

* Part this, part MentalFusion is required on the behalf of the pilots in ''Film/PacificRim'' so they can control the powerful [[HumongousMecha Jaegers]] with a neural link. More than one pilot is necessary to take the mental strain of moving a giant robot with your mind, so Jaeger pilots must be "Drift-compatible" in order to ensure that they can work together effectively. To facilitate this, most (though not all) pilot pairs are family members or romantic couples.
* The events of ''Film/UpstreamColor'' are driven by the lifecycle of a parasitical organism that creates a psychic link between those it's inhabited.

* In ''Film/AvengersAgeOfUltron'', twins Quicksilver and Scarlet Witch are linked this way (at least, Scarlet Witch, as TheEmpath, feels what Quicksilver feels. It's never mentioned whether the link goes both ways). When [[spoiler:Quicksilver dies,]] it doesn't do the same to Scarlet Witch, though judging from the way she screams when it happens, it is pretty bad for her, too.

* ''Film/TheSuicideSquad''. Starro's PuppeteerParasite's are an extension of him, so when his giant {{Kaiju}} form gives a MightyRoar they mimic it, and when Polka-Dot Man slices a limb off, everyone taken over by him [[HurtFootHop stands on one leg and clutches the other]] while screaming in agony.

* In ''Film/YourHighness'', PsychopathicManChild native king Marteetee has a cauldron of magic mustard that manifests a five-headed hydra in his gladiator arena when he sticks his hand into it. Unfortunately, if one of the hydra heads is lopped off, he loses his corresponding finger. When he dies and plunges face-first into the cauldron, a giant agonized face emerges from the arena floor.

* This is the very premise of ''LetsPlay/LifeSMP'' Season 3, also known as ''Double Life SMP''. Each player's health-bar is linked to another (officially refered to as a "soulmate"), if one takes damage so will the other, and [[CantLiveWithoutYou if one dies, the other does as well]]. Since the game doesn't directly tell people who their soulmate is, most of the first day was spent with everyone running around punching each other to find their partner (And in Jimmy and Tango's case, they didn't find out until the latter lost his first life).

[[caption-width-right:330: Do you know how long it takes to hang a dragon? Rick sure does.]]

->'''Xamot:''' ''[grunts in pain]''\\

'''Alpine:''' Terrific! Pass ''this'' on! ''[punch]''

* A What If issue of ''ComicBook/IncredibleHulk'' had Bruce fail to push Rick into the ditch to save him from the gamma bomb. Instead the blast was effectively filtered through Bruce's body before irradiating Rick, which telepathically bonded the latter to the former in both his egos. When General Ross tries to exploit their connection to entrap the Hulk, he neglects to treat Rick's radiation poisoning until it's too late and Rick dies. This drives the Hulk murderously insane, and he ends up killing the Fantastic Four and Iron Man in his rampage before Thor can finally put him down.

** [[spoiler:Petra Bellweather]] innocently taps her pen on her desk, but actually synchs an enemy officer's heartbeat to the tapping. The faster she taps, the higher his heart rate. She continues until his heart gives out and he drops dead.

* At one point in ''Anime/TheVisionOfEscaflowne'', Van became synchronized to Escaflowne. While this allowed him to win the battle in that episode, it also resulted in him taking serious injuries in the same places the Escaflowne was damaged, and the only way to treat them was to get Escaflowne fixed (with poor Van screaming and [[HeroicBSOD BSODing]] in pain as it's done), since fixing Escaflowne is like fixing any machine, only more complex. And considering that Escaflowne [[PaintItBlack turned black]] when it happened, synchronization could also count as a SuperpoweredEvilSide.

* At one point in ''Anime/TheVisionOfEscaflowne'', Van became synchronized to Escaflowne. While this allowed him to win the battle in that episode, it also resulted in him taking serious injuries in the same places the Escaflowne was damaged, and the only way to treat them was to get Escaflowne fixed (with poor Van screaming and [[HeroicBSOD BSODing]] in pain as it's done), since fixing Escaflowne is like fixing any machine, only more complex and taking the mental/physical link in consideration. And considering that Escaflowne [[PaintItBlack turned black]] when it happened, synchronization could also count as a SuperpoweredEvilSide.

** After Iris is damaged by a computer terminal explosion caused by the deceased Cyber Peacock, Colonel breaks military regulations and goes to the base where she is being treated in a stasis pod to try and save her. He finds Zero and insists on fighting him despite the fact that Zero has already gotten a vaccine for Iris, and tells Zero that it is their desinty to fight. Zero holds nothing back, and slices of Colonel's right arm with his saber. Moments later, Iris's right arm corrodes in the pod. Zero realizes that Iris once said she and Colonel are "two people, one person" and that he is hurting her by damaging Colonel. Despite all this, Colonel refuses to surrender, and charges at Zero one last time. Zero, with an agonizd expression on his face, reluctantly kills him by slicing him in half, [[ShootTheDog knowing full well that doing so would cause Iris to die as well]]. Iris later jolts out of her sleep and breaks out of her pod, and says she feels pain as if there were a hole in her chest. After instinctively going to her brother's corpse, she inadvertently fuses with him and is transformed into a Ride Armor. After she causes some destruction and kills Reploids in the base, Zero smashes the armor and pulls her out of it. Iris tells Zero that even though her brother is dead and Colonel hurt a lot of his own friends due to his foolishness, she was happy to have spent time with Zero. She then dies moments later because of Colonel's death directly affecting her.

* This is the very premise of ''LetsPlay/LifeSMP'' Season 3, also known as ''Double Life SMP''. Each player's health-bar is linked to another, if one takes damage so will the other, and [[CantLiveWithoutYou if one dies, the other does as well]]. The official series description refers to these duos as "soulmates".

* In ''Literature/{{Mouse}}'', Priest helps Mouse use his powers to give [[FriendlyGhost Anna]] a physical body that's magically linked to his. Now they can feel each other's pain and emotions and catch snippets of each other's thoughts, and Anna complains about the taste when Mouse drinks tea.

* ''Literature/TrintonChronicles'' Aurora is linked to her duplicates the same way by feeling their pain and their death, kind of screws her up mentally.
* In ''Literature/DeadWest'', this seems to be the side-effect of the Oaths, at least when they are properly offered and accepted. [[spoiler: After the Porcelain Doctor accepts Gervas' Oath for protection, he heals Gervas easier even without actually using his HealingHands, his PowerIncontinence seems to concentrate on Gervas, and they are able to pull BackToBackBadasses notably easily, BattleCouple -style, without actually exchanging words or practicing.]]
* ''Wiki/SCPFoundation'', [[http://www.scp-wiki.net/scp-607 SCP-607 ("Dorian")]]. When SCP-607 bonds with someone, anything that happens to it (physical or emotional) will also happen to that person. It also happens to be [[DrivenToSuicide suicidal]], which means anyone it bonds with will not last much longer.

* In the ''Series/RedDwarf'' episode [[RedDwarfSeasonIVJustice "Justice"]], the Justice Field reflects any criminal acts back upon the actor. If you try to light the sheets on fire, you end up lighting yourself on fire (and the sheets stay unburnt). "It's the ultimate deterrent," as Rimmer says. This situation leads to a marvelous fight in which hitting your opponent hurts ''you'' instead. The bad guy, a Simulant (think the Terminator with ''really'' bad BO) [[TooDumbToLive is too dumb to realize what's going on]]. So he tries shooting Lister and throwing a knife at him. Twice. Lister even draws a target on his groin and presents it for kicking. Then he hands the Simulant a few giant vases, to be smashed over Lister's head. The Simulant then tries to strangle Lister, thus strangling himself. With the bad guy defeated, [[{{Cloudcuckoolander}} The Cat]] turns up, armed with a spade...

* In ''Series/RedDwarf'', the Justice Field reflects any criminal acts back upon the actor. If you try to light the sheets on fire, you end up lighting yourself on fire (and the sheets stay unburnt). "It's the ultimate deterrent," as Rimmer says. This situation leads to a marvelous fight in which hitting your opponent hurts ''you'' instead. The bad guy, a Simulant (think the Terminator with ''really'' bad BO) [[TooDumbToLive is too dumb to realize what's going on]]. So he tries shooting Lister and throwing a knife at him. Twice. Lister even draws a target on his groin and presents it for kicking. Then he hands the Simulant a few giant vases, to be smashed over Lister's head. The Simulant then tries to strangle Lister, thus strangling himself. With the bad guy defeated, [[{{Cloudcuckoolander}} The Cat]] turns up, armed with a spade...

** [[HumongousMecha Titan]] Princeps suffer physical pain when their titans suffer battle damage. Not merely the Princeps, but the key members of his crew also suffer such pain, in varying degrees, particularly the Moderati.

** Taken even further in ''Anime/DigimonTamers''. First shown with Takato who's strong bond with his partner Guilmon causes him to start feeling Guilmon's pain at certain times (starting with the battle with the tiger Deva Mihiramon) as well as allowing him to mentally and emotionally connect with Guilmon, at times even allowing him to lend Guilmon strength. [[spoiler: After the main trio Bio-Merge with their Digimon, they discover that all three of them feel now feel their partner's pain when they fight the D-Reaper in the real world.]]

* At one point in ''Anime/TheVisionOfEscaflowne'', Van became synchronized to Escaflowne. While this allowed him to win the battle in that episode, it also resulted in him taking serious injuries, and the only way to treat them was to get Escaflowne fixed (with poor Van screaming and [[HeroicBSOD BSODing]] in pain as it's done, since fixing Escaflowne is almost like fixing any machine, only more complex and taking the mental/physical link in consideration. And considering that Escaflowne [[PaintItBlack turned black]] when it happened, synchronization could also count as a SuperpoweredEvilSide.

* The whole plot of ''Manga/{{Loveless}}'' revolved around the empathic connection between "Fighters" and "Sacrifices", in which the first are capable of commanding spells while the second suffer the effects of attacks in combat. The connection between both parties is vital to ensure victory and survival.