History Main / SplitPersonalityMerge

* Music/{{Eminem}}'s [[KayfabeMusic kayfabe]] shows this happening over time. At the start of the story, Slim Shady [[SplitPersonalityTakeover takes control over the formerly positive]] ConsciousHipHop artist and wipes his original personality. Slim's personality forms a bleach-stain even on Eminem's increasing appearances in his discography, causing the line between the two to get blurred, until Marshall kills him in "When I'm Gone" due to him spreading into his personal life. Following [[CreatorBreakdown Eminem's drug addiction and depression nearly killing him]], Slim comes back from the dead BloodierAndGorier than ever on ''Relapse'', but is then PutOnABus for most of ''Recovery'' (having had a [[BoltOfDivineRetribution painful reminder]] to stay on his best behaviour, courtesy of God), while a now dark-haired and soberly-dressed Eminem airs sincere joy about his CreatorRecovery. The following album, ''The Marshall Mathers LP 2'', after Eminem was more comfortable in sobriety, shows a reblonded Eminem having found a comfortable medium with Slim, embracing Slim's exuberance and productive rage as well as with Eminem's [[TheParagon compassion and inner strength]]. The video for "The Monster" shows Slim locked up in Eminem's mind, but helping him out with his lyrics, while the song itself reminds us that they get along; the AlbumClosure tells us that the two of them are the same.

* [[IAmWhatIAm Accepting one's Shadow self]] in ''VideoGame/{{Persona 4}}'' transforms it into a Persona, which isn't quite merged but does act as a GuardianEntity instead of an EnemyWithout.

* As the Act 2 of ''VideoGame/Cyberpunk2077'' goes on, PlayerCharacter V starts affecting the mannerism of [[spoiler:Johnny Silverhand, after being infected by a biochip containing a copy of his mind]], they're told it's only a matter of weeks until their personality [[DeathOfPersonality gets completely overwritten by]] [[spoiler:Silverhand's]], and the rest of the game is them trying to find a way to stop it.

-->"The bits and bytes that have made up your life so far... can you say for sure that they are not just copies of someone else's?"

** In ''Anime/MobileSuitGundam00'', Allelujah Haptism temporarily merges with his violent SplitPersonality Hallelujah Haptism to become "the SuperSoldier" with the piloting skills of two men, or [[FanNickname as fans call him]], "Doublelujah." This is visually demonstrated by the fact that Allelujah always has his right eye covered by his hair, while when Hallelujah takes over, he sweeps the hair over to cover his left eye instead. When both personalities work together, both eyes are exposed (and he speaks with both voices and personalities in turn).

* ''Manga/RosarioPlusVampire'': Even after [[spoiler: the destruction of the [[RestrainingBolt rosary]] and her seeming [[DeathOfPersonality demise]], Outer Moka's soul still exists within Inner Moka's body, and by the final chapter, the two have become one, signified by Inner Moka's [[MulticoloredHair silver hair turning pink at the ends]]. This merger overlapped so completely with Inner Moka's own [[DefrostingIceQueen defrosting]] that nobody other than her father (not even newly merged Moka herself) realized it was happening at first]].

* ComicBook/DeathsHead II gained independence after the Minion cyborg assimilated the minds of 105 of the most deadly minds in the universe, only to have its last target (the original ComicBook/DeathsHead) take over its programming and form a gestalt personality.

* ''Manga/RosarioToVampire'': Even after [[spoiler: the destruction of the [[RestrainingBolt rosary]] and her seeming [[DeathOfPersonality demise]], Outer Moka's soul still exists within Inner Moka's body, and by the final chapter, the two have become one, signified by Inner Moka's [[MulticoloredHair silver hair turning pink at the ends]]. This merger overlapped so completely with Inner Moka's own [[DefrostingIceQueen defrosting]] that nobody other than her father (not even newly merged Moka herself) realized it was happening at first]].

* ''Animation/BoBoiBoy'': The titular hero has ElementalPowers, and each element has a personified form that he can turn into. [[LiteralSplitPersonality Multiple elementals can be summoned at a time]], typically three at a time via "Triple Split", and can later merge back to make the whole [=BoBoiBoy=] again. Initially, if he used his Triple Split ability for too long, [[EquivalentExchange it could have damaging effects on his memory]], and therefore the elementals had to merge back as quickly as possible.

* ''Animation/BoBoiBoy'': The titular hero has ElementalPowers, and each element has a personified form that he can turn into. [[LiteralPersonalitySplit Multiple elementals can be summoned at a time]], typically three at a time via "Triple Split", and can later merge back to make the whole [=BoBoiBoy=] again. Initially, if he used his Triple Split ability for too long, [[EquivalentExchange it could have damaging effects on his memory]].

** Sora managed to keep his human form as a Heartless with some help from Kairi, and his Nobody Roxas didn't get any of his memories. This meant Roxas's appearance and eventual personality were completely different from Sora's, and while they ''do'' merge at first, Sora eventually questions the wisdom of the decision and seeks to resurrect Roxas as his own person. Sora doesn't know it, but he's ''also'' merged with Xion, an ArtificialHuman made out of memories stolen from him in a previous adventure, who also has her own personality.
** Kairi and Naminé are in a similar boat: since Kairi literally [[IncorruptiblePurePureness cannot become a Heartless]], she's able to retain her body and memories when Naminé is born, leaving Naminé with nothing but the barest of existence to call her own. The pair eventually merge, although this too may be undone.

* Crazy Jane of ''Comicbook/DoomPatrol'' had 64 distinct personalities when introduced, each with its own superpower. Over the course of her initial run she began integrating them. Two in particular, Baby Doll and Scarlet Harlot, merged to become Baby Harlot. (She was based on Truddi Chase and the Troops, who catalogued 92 people, never integrated, and despised the idea.)

* The ComicBook/GreenGoblin has undergone this after his 1996 comeback, the Goblin previously veering between being an outright SplitPersonality of ComicBook/{{Norman Osborn}}, a psychotic break from reality and the power fantasy of an unstable CorruptCorporateExecutive who just won the SuperpowerLottery. Naturally, the amalgation of a mentally ill white collar criminal with his homicidal maniac alternate persona did not exactly make things better- the new Norman Osborn was a MagnificentBastard who developed particularly twisted views on his emnity with Franchise/SpiderMan and graduated from millionaire industrialist to head of S.H.I.E.L.D. (because HumansAreMorons). Recently, the Goblin has shown signs of making a comeback, in the form of delusions and homicidal mania.
** And very recently, Osborn was purged of the Goblin formula entirely. While he's been BroughtDownToNormal, he sees the sudden lucidity as an advantage in crushing his enemies, and the "good" Norman that used to appear during his early bouts of amnesia is entirely absent.
%%* ''Comicbook/GreenLantern'' has Carol growing more stronger when she accepted the Star Sapphire ring willingly to the point that she regains control of herself in her Star Sapphire form this time.
* Doc Samson once pretended to have done this to [[ComicBook/TheIncredibleHulk the Hulk and Bruce Banner]], via EpiphanyTherapy. But [[FailureIsTheOnlyOption eventually the change in premise became too much of a problem for the Hulk's title]], and the writers made use of the fact that Therapy Does Not Work That Way to establish that Samson had really just created a new, if more stable, alternate. [[CanonDiscontinuity Tossing out the fact that Doc Samson wasn't really in control of the process and didn't fully understand what was happening at the time.]]

* ''ComicBook/SupermanReborn'' reveals [[spoiler:the creation of the ''ComicBook/{{New 52}}'' continuity caused Franchise/{{Superman}} to be [[LiteralSplitPersonality separated]] into his pre-''ComicBook/{{Flashpoint}}'' and ''[=N52=]'' selves, explaining why were there two versions of Superman flying around at the end of the ''New 52'', when no other character displayed such problem. At the end of the story, they merge into a single, complete version of Superman.]]

* ''ComicBook/XMen'': Professor X's wayward son Legion had his personalities integrated... into one guy who was ''far'' worse than his previous selves put together. The result was the ComicBook/{{Age of Apocalypse}}. Before, each of his selves only had access to one mutant power, and the good and neutral personalities acted as somewhat of a restraint on the evil one. The amalgamated version became an [[TheUnfettered utterly ruthless]] WellIntentionedExtremist with access to ''all'' of Legion's many powers ([[SuperpowerLottery which turned out to be stronger and more varied than anyone realized]]).
** Later, as the focus character of the X-Men: Legacy title, CharacterDevelopment allows him to do this without going off the rails.

Minus the superpowers, this is the RealLife scenario that until very recently was believed to be the best solution by doctors working with multiples clear back to [[https://books.google.com/books?id=oDlq6EtyR8wC&dq=%22My+life+as+a+dissociated+personality%22&printsec=frontcover&source=bl&ots=jG6Ha_RbAf&sig=Y_R015UyfFOxrGfDhIjzPb3V9sA&hl=en&ei=bA34SYyBM6b4tAO336nsDg&sa=X&oi=book_result&ct=result&resnum=1#v=onepage&q=%22My%20life%20as%20a%20dissociated%20personality%22&f=false Dr. Morton Prince in the early 1900s]]; many books on multiple personality disorder follow this storyline of helping patients integrate their numerous identities to achieve mental health. The many books on MPD/DID written by professional psychologists and published in the '80s and '90s [[note]]not official, psychiatric case studies but popular accounts, novels really, which purported to be based on (sometimes [[VeryLooselyBasedOnATrueStory very loosely]]) these doctors' work with abuse survivors who might have been multiple.[[/note]] tend to end with Integration as a HappyEnding, either Disneyesque [[note]]As multiples began speaking up for themselves in the late '80s-early '90s, rather than letting mental health professionals have full control of the narrative, some observed that many doctors, and numerous books on the subject, seemed to equate "integrated" with "[[{{Housewife}} June Cleaver]]."[[/note]] or a spiritual experience akin to a conversion. Actual multiples report YMMV on this experience; while merging has indeed been helpful for some[[note]]Chris Costner-Sizemore, the real ''Film/TheThreeFacesOfEve'' integrated permanently and really did feel it was the answer[[/note]], others who have gone through it have ''deliberately'' de-integrated themselves later on, feeling that the whole is ''less'' than the sum of the parts.[[note]]Sybil and Billy Milligan, arguably the two most famous cases of the 1970s, both ended up de-integrating and felt much better for it.[[/note]] Still others can integrate and separate at will, but report it as an unpleasant experience. ''Literature/WhenRabbitHowls'' is a notable autobiography covering that side of the subject, written by members of a multiple collective who spoke out vehemently against this idea as a form of murder. To multiples who feel this way, it's better to learn how to communicate and work together as a SplitPersonalityTeam or MindHive. Psychology professionals have come to accept this viewpoint in recent years as well, believing that having these people learn to safely coexist is just valid as attempting to merge them.

* Done uniquely in ''Anime/DanganRonpa3''. [[spoiler:One of the main characters, Hajime, underwent a surgery that replaced his personality with a different one, which was then renamed Izuru. After [[VisualNovel/SuperDanganRonpa2 the events of the second game]], the two of them managed to reach an accord and merge, signified by heterochromia--one eye Hajime's green, the other Izuru's red. However, rather than one of them being dominant, the resulting persona has traits from them ''both'', and upon being asked which name he goes by in the OVA simply says "either is fine".]]

* In ''VideoGame/LaPucelle'', [[spoiler:Eclair]] confronts and merges with Dark [[spoiler:Eclair]] who is [[spoiler:her]] desire to be free and normal.

* ''{{Anime/Bakugan}}'': [[TheHeavy Masqurade]], the sadistic, evil, and powerful Brawler that plagues the main cast, is actually [[spoiler:''Alice,'' the soft-spoken FriendToAllLivingThings, [[NonActionGuy Non-Action Girl]] of the team. She was around her [[MadScientist grandfather's]] laboratory at the time of an accident, creating a JekyllAndHyde personality that occasionally hijacked her. After [[TomatoInTheMirror she finds this out]] she initially runs away to avoid harming the team. Ultimately, she comes to peace with and lays the Masquarade personality to rest, who becomes a SpiritAdvisor to her in Brawling. This also leads to her becoming an ActionGirl (who still keeps her NiceGirl personality).]]
* ''Manga/SoulHunter'' has this with Taikoubou and [[spoiler:Ou Eki]]. They later [[spoiler:merge together to become Fukki]], although [[spoiler:Taikoubou is the main, dominating personality]].

* ''Manga/{{Change 123}}'' is all about trying to merge the personalities of Motoko and [=HiFuMi=] [[spoiler:and Zero]].
%%* Happens at the end of the ''Manga/{{Mahoraba}}'' manga.

* Often overlooked in the English dub of ''Anime/YuGiOh'', Yugi and the pharaoh usually combine their minds when dueling. The reason this is overlooked is because Yugi merged with the pharaoh looks pretty much exactly like the pharaoh all by himself. On account of the pharaoh looking like an older version of Yugi.
* In ''Anime/YuGiOhGX'', this occurs during his final duel against Yubel when Jaden accepts that he is the Supreme King, and no longer fears or denies that power.
* In ''Manga/{{Bleach}}'', Ichigo's power manifested in the forms of Zangetsu, his Zanpakuto, and his Inner Hollow. In time, [[spoiler: he comes to dominate both of them, learning how to use their power for himself. He also tends to take on aspects of their personality and appearance when using their power, such as the coat he acquires in Bankai mode and the mask and personality changes that accompany his Hollowfication. Recently, Zangetsu and the Inner Hollow merged themselves while Tensa Zangetsu was trying to teach Ichigo the [[EleventhHourSuperPower Final Getsuga]]. The result seems to be Tensa Zangetsu wearing a white robe instead of a black one, and having the top part of the Inner Hollow's super evolved mask. However, his personality seems to remain as that of Zangetsu's. Ichigo then merges with THIS personality, and takes on its confidence and... moodiness. Also the inner hollow turns out to be a merger of his Actual Soul Reaper powers and the hollow powers, while Zangetsu is his Quincy powers.]]
* In ''[[Anime/PrettySammy Magical Project S]]'', Misao becomes a lot stronger mentally when she accepts her Pixy Misa DarkMagicalGirl persona. (And has full control when turning into Pixy Misa later.)
* Hikaru and [[EnemyWithout Nova]] in ''Manga/MagicKnightRayearth'', when Hikaru comes to realize [[spoiler: Nova was created from Hikaru's feelings of guilt and regret for killing Princess Emeraude, and finally learns to accept these feelings and forgive herself]].

* ''Manga/WChange'' both inverts this, then plays it straight. Maki's two personalities used to be one entity -- with the "light" side representing her happiness and joy and the "dark" sight representing her anger and sorrow, but they diverged into two separate beings at some point. Later, the personalities merged back together, allowing Maki to switch between her two sides at whim.

* Done uniquely in ''Anime/DanganRonpa3''. [[spoiler:One of the main characters, Hajime, underwent a surgery that replaced his personality with a different one, which was then renamed Izuru. After [[VisualNovel/SuperDanganRonpa2 the events of the second game]], the two of them managed to reach an accord and merge, signified by heterochromia--one eye Hajime's green, the other Izuru's red. However, rather than one of them being dominant, the resulting persona has traits from them ''both'', and upon being asked which name he goes by in the OVA simply says "either is fine".]]
* ''Manga/KaguyaSamaLoveIsWar'' has a downplayed example. Kaguya explicitly does not have split personality disorder, but she vacillates wildly between her emotional, vulnerable "self" and the "self" that is paranoid and [[DarkAndTroubledPast trauma]]-based. Ice Kaguya (as the latter is known) thinks of her other as stupid, and Kaguya-chan thinks of her other as heartless. After several internal screaming matches, the two accept that they both have a reason for existing, and Kaguya comes closer to being her true self: a girl who can protect herself from her [[AbusiveParents family]] if needed, but who is also able to appreciate the peace and friendships that give life meaning.

* Doc Samson once pretended to have done this to [[ComicBook/TheIncredibleHulk the Hulk and Bruce Banner]], via EpiphanyTherapy. But [[FailureIsTheOnlyOption eventually the change in premise became too much of a problem for the Hulk's title]], and the writers made use of the fact that Therapy Does Not Work That Way to establish that Samson had really just created a new, if more stable, alternate. [[CanonDiscontinuity Tossing out the fact that Doc Samson wasn't really in control of the process and didn't fully understand what was happening at the time.]]
* ''ComicBook/XMen'': Professor X's wayward son Legion had his personalities integrated... into one guy who was ''far'' worse than his previous selves put together. The result was the ComicBook/{{Age of Apocalypse}}. Before, each of his selves only had access to one mutant power, and the good and neutral personalities acted as somewhat of a restraint on the evil one. The amalgamated version became an [[TheUnfettered utterly ruthless]] WellIntentionedExtremist with access to ''all'' of Legion's many powers ([[SuperpowerLottery which turned out to be stronger and more varied than anyone realized]]).
** Later, as the focus character of the X-Men: Legacy title, CharacterDevelopment allows him to do this without going off the rails.
* The Green Goblin has undergone this after his 1996 comeback, the Goblin previously veering between being an outright SplitPersonality of ComicBook/{{Norman Osborn}}, a psychotic break from reality and the power fantasy of an unstable CorruptCorporateExecutive who just won the SuperpowerLottery. Naturally, the amalgation of a mentally ill white collar criminal with his homicidal maniac alternate persona did not exactly make things better- the new Norman Osborn was a MagnificentBastard who developed particularly twisted views on his emnity with Franchise/SpiderMan and graduated from millionaire industrialist to head of S.H.I.E.L.D. (because HumansAreMorons). Recently, the Goblin has shown signs of making a comeback, in the form of delusions and homicidal mania.
** And very recently, Osborn was purged of the Goblin formula entirely. While he's been BroughtDownToNormal, he sees the sudden lucidity as an advantage in crushing his enemies, and the "good" Norman that used to appear during his early bouts of amnesia is entirely absent.

* In the schoolgirl comic book ''Julie's Jungle Cousin'' Sue has two personalities: Jungle Sue, a gender-flipped Franchise/{{Tarzan}} who speaks YouNoTakeCandle, acts on instinct and is capable of daring physical feats; and Stuttering Sue, who speaks grammatical English with a stutter and is a physical klutz. By the end of the comic she has managed to integrate the two into one articulate, athletic personality.
* Crazy Jane of ''Comicbook/DoomPatrol'' had 64 distinct personalities when introduced, each with its own superpower. Over the course of her initial run she began integrating them. Two in particular, Baby Doll and Scarlet Harlot, merged to become Baby Harlot. (She was based on Truddi Chase and the Troops, who catalogued 92 people, never integrated, and despised the idea.)

* Occurs to [[WesternAnimation/MyLittlePonyFriendshipIsMagic Twilight Sparkle]] near the latter end of ''FanFic/TheImmortalGame''. Earlier in the story, the psychological trauma of being transformed into [[SuperpoweredEvilSide Nihilus]] had caused her mind to {{split|Personality}} in two -- the dominant, [[ActualPacifist peaceful-to-a-fault]] Sparkle, and the more brutish Twilight. The two personalities spend quite some time [[TalkingToThemself arguing]], with Twilight pushing for a merge to restore themself to a full and equal mind, but Sparkle being too afraid that Twilight will pull a SplitPersonalityTakeover and be as [[HeWhoFightsMonsters monstrous as Nihilus was]]. Eventually, [[spoiler:[[BigBad Titan]] captures Sparkle and tortures her. The pain and desperation causes Sparkle to accept Twilight and fuse back with her, recreating the ''real'' Twilight Sparkle]]. Cue [[HesBack asskicking]].

* Fluttershy and Erica eventually perform this in ''FanFic/BecomingPonies''. As do one half of Twilight and Isaac.
* [[http://www.tthfanfic.org/Story-11037/Mediancat+The+Sum+of+Their+Parts.htm The Sum of Their Parts]] is a fanfic that begins by establishing that Faith (from Series/BuffyTheVampireSlayer) [[http://www.tthfanfic.org/Story-10602/Mediancat+April+10+1997.htm is actually an alternate personality]] for WesternAnimation/{{Daria}} Morgendoffer produced to handle her rage over [[spoiler:her family's brutal murder]]. Eventually she winds up in a fight with [[spoiler:Glorificus who steals the mental energy maintaining their separation]]. Then [[spoiler:Willow pulls the same trick on Glory/Ben]]. [[spoiler:Daria's and Faith's minds work together to become "reason, backed by intuition... more than the sum of her parts," while Glory/Ben become completely paralysed by indecision: "less than the sum".]]

* In ''Fanfic/{{Flinch}}'', Sheik is the embodiment of all of Zelda's repressed anger and violent desires. She's a PsychoForHire while Zelda is an ActualPacifist. Eventually, Zelda comes to terms with her aggression, merges Sheik, and [[spoiler:gives Samus a NoHoldsBarredBeatDown]].

* Despite providing the picture, ''Series/{{Jekyll}}'' averts this. Even though Jackman and Hyde agree to work together, they retain their individual personalities and [[SuperpoweredEvilSide powers or lack of them]]. Their alliance is simply a case of switching voluntarily depending on which would be most useful at any time, and both of them agreeing to devote their respective talents towards the common goal of saving Jackman's family.
* At the end of season 2 of ''Series/CloakAndDagger2018'', it's ambiguous whether this has happened to Bridget and Meyhem, or whether Meyhem's still in control but ''listening'' to Bridget in her head.

* This is a central mechanic of the game, ''Vox'', where characters incorporate the voices in their head as a part of themselves they have 'forgotten,' growing closer to perfection each time.

* The goal of the Multiple Men in ''TabletopGame/BleakWorld''. Unlike most [[GoneHorriblyWrong Experiments]], the Multiple Men would rather live with their personalities than silence them and have various methods of getting along.

* Happens with [[spoiler:Kain]] and [[spoiler:[[EnemyWithout Dark Kain]]]] in ''[[VideoGame/FinalFantasyIVTheAfterYears Final Fantasy IV: The After Years]]''.
** This happens to [[spoiler:Cecil]] as well. It turns out that [[spoiler:the [[CastingAShadow Dark Knight]] aspect of Cecil's personality that he cast away [[VideoGame/FinalFantasyIV seventeen years prior]] in order to accept the powers of a [[ThePaladin Paladin]] comes back to life and becomes Cecil's EnemyWithout, serving as a boss late in the game. Upon defeat, the Dark Knight [[BetaTestBaddie questions his identity]], causing Cecil to apologize for repressing this part of his life for so long and pull a YouAreNotAlone on his darker half. This event is crucial for [[HesBack rousing Cecil out of his]] HeroicBSOD (thus restoring his resolve and in-game stats), although Cecil doesn't regain his Dark Knight abilities (no, ''VideoGame/{{Dissidia|FinalFantasy}}'' doesn't count... probably).]]
* In ''VideoGame/LightningReturnsFinalFantasyXIII'', [[spoiler:Lightning and Lumina merge once Lightning accepts the parts of herself she viewed as "weaknesses", which manifested as Lumina.]]

* In ''Franchise/KingdomHearts'', someone whose heart is lost to darkness, but had above-average strength of will, can find that not only does their stolen heart become an instinct-driven [[TheHeartless Heartless]], but their leftover body gets back up and turns into an emotionless [[HumanoidAbomination Nobody]]. Killing or melding both of these will resurrect the original person. The Nobody can eventually grow a new heart with enough time and experiences, which makes their subhuman treatment in ''VideoGame/KingdomHeartsII'' rather morally dubious once it's revealed, but the resurrected human retains all of the Nobody's memories and merges any new heart with their own, so most of them are quite fine with it afterward. If you're Sora or Kairi, things get more complicated:
** Sora managed to keep his human form as a Heartless with some help from Kairi, and his Nobody Roxas didn't get any of his memories. This meant Roxas's appearance and eventual personality were completely different from Sora's, and while they ''do'' merge at first, Sora eventually questions the wisdom of the decision and seeks to resurrect Roxas as his own person. Sora doesn't know it, but he's ''also'' merged with Xion, an ArtificialHuman made out of memories stolen from him in a previous adventure, who also has her own personality.
** Kairi and Naminé are in a similar boat: since Kairi literally [[IncorruptiblePurePureness cannot become a Heartless]], she's able to retain her body and memories when Naminé is born, leaving Naminé with nothing but the barest of existence to call her own. The pair eventually merge, although this too may be undone.
** [[EnemyWithout Vanitas]] tries to force this with Ventus at the climax of ''[[VideoGame/KingdomHeartsBirthBySleep Birth by Sleep]]'', which would cause TheEndOfTheWorldAsWeKnowIt if he succeeded. Ven eventually manages to break the merger at the cost of sending both halves into a ten-year-long coma, which they spend trapped inside Sora's heart. Combined with the previously-mentioned mergers, Sora's heart is quite the clown car by the time of ''[[VideoGame/KingdomHearts3DDreamDropDistance 3D]]'', with no less than four other hearts inside him. Xemnas even outright asks Sora how much of him can really be called ''him'' after merging with that many other people:
-->"The bits and bytes that have made up your life so far... can you say for sure that they are not just copies of someone else's?"
* In the final quest of ''[[VideoGame/FinalFantasyXIV Final Fantasy XIV: Shadowbringers]]'', [[spoiler:this happens to the Warrior of Light and the Warrior of Darkness shortly after realizing they're fragments of the same soul.]]
* Not quite a merger, but in ''VideoGame/VampireTheMasqueradeBloodlines'', in the climactic dialog with [[spoiler: Jeanette/Therese]], with high enough stats you can persuade them to make amends and tolerate each other, in which case they bury the hatchet and peacefully coexist. Speaking with them later on reveals they're still separate entities, but apparently much more aware of each other [[spoiler:and the ensuing character is named 'Tourette' by the game.]]
* Fei in ''VideoGame/{{Xenogears}}'' merges with no less than three (possibly four, though that one was an EmptyShell) alternate personalities after convincing them to. This is remarkable since he wasn't the original, but ''the third'' personality.

* It's not fully explained, but this happens in the Dimensional Vortexes in the DS re-release of ''VideoGame/ChronoTrigger''.
* The ''VideoGame/FalloutNewVegas'' [[DownloadableContent DLC]] ''Dead Money'' has Dog and God, a Nightkin with two personalities: the dumb, friendly, always-loyal, always-hungry [[MeaningfulName Dog]]; and the cold, calculating, intelligent, {{Jerkass}} ControlFreak [[JerkWithAHeartOfGold with a heart of gold]] [[MeaningfulName God]]. Essentially, they are the Id and Superego of one single personality, and eventually you have the option of merging the two personalities into one, or have either Dog or God [[SplitPersonalityTakeover take over completely]]. If you merge the two, Dog and God will finally put aside their differences for a brief moment to say thanks and goodbye to you before merging. The merged personality has no memories at all, but has a vague feeling like you've helped him, even though he doesn't know who the hell you are.
* In the [[MultipleEndings normal and good endings]] of ''VideoGame/TalesOfSymphoniaDawnOfTheNewWorld'', [[spoiler:Ratatosk's personality comes to terms with the part of himself that is Emil and the two accept each other as parts of a whole.]]

* Inverted in ''VideoGame/MassEffect3'' to [[spoiler: the geth, formerly a [[MindHive cooperative mass of programs,]] allowing them to become self-aware individuals, after the recently individualized Legion [[HeroicSacrifice merges himself with the Consensus.]]]]
* [[IAmWhatIAm Accepting one's Shadow self]] in ''VideoGame/{{Persona 4}}'' transforms it into a Persona, which isn't quite merged but does act as a GuardianEntity instead of an EnemyWithout.

* [[spoiler:Vergil's human half, V,]] does this with [[spoiler:his demonic counterpart, Urizen,]] in ''VideoGame/DevilMayCry5'', though they leave behind [[spoiler:Griffon, Shadow, and Nightmare, Nelo Angelo's emotional baggage]].

* Occurs in [[spoiler:Ren's good ending]] in ''VisualNovel/DramaticalMurder'' with [[spoiler:Aoba and his SuperpoweredEvilSide, who he has come to realize isn't truly evil but lonely and acting out to get his attention]].

* Mingmei Wu and Professor Sorgaz in ''Webcomic/TheWotch'', once Mingmei is made aware of her status as a [[GenderBender gender bent]] teacher dunked in the FountainOfYouth and the origional personality reappears. Perhaps a slight twist on this trope, as well; Mingmei is perfectly willing to go away so Professor Sorgaz can return to his normal life. It is ''Sorgaz'' who proposes merger, claiming she already has a better life than he ever did (He proposes merging the best of both worlds-- her friends, his bank account).
* This is one of the possible explanations for the ending of the Aiden and Brownwyn arc in ''Webcomic/{{Misfile}}''. It wasn't made terribly clear, but Rumisiel did force the Wraith-thing to into Bronwyn's psyche and told it to stay there, and Bronwyn did regain her affection for Aiden as a result.

* ''WesternAnimation/RickAndMorty'': In the episode "Rest and Ricklaxation", Rick and Morty get split into "healthy" halves and "toxic" halves. Rick realizes they have to merge back to save the lives of their toxic halves, [[spoiler:but Morty refuses to do so and runs away. Eventually, Rick tracks him down and forcefully remerges him.]]
* ''WesternAnimation/OKKOLetsBeHeroes'': K.O. and Turbo K.O. can merge to form Perfect K.O. so long as one doesn't overpower the other. [[spoiler:The GrandFinale sees them merge permanently after K.O. accepts T.K.O. as being him instead of just a part of him, resulting in K.O.'s outfit becoming darker and him now having T.K.O.'s fang.]]

[[folder:Anime & Manga]]

** In ''Anime/DragonBallGT'', Good Buu merges with Uub, the reincarnation of Kid Buu, to become Majuub.

* A [[https://anti-catharsis.tumblr.com/post/183557416601/can-i-just-go-ahead-and-say-how-great-the-writing fan commentary]] on the ''WesternAnimation Miraculous Ladybug'' episode ''Oblivio'' describes it in terms similar to this trope.

** In ''Anime/DragonBallGT'', Good Buu merges with Uub, the reincarnation of Kid Buu.

** Piccolo and Kami, who had become a LiteralSplitPersonality decades earlier. (With a little {{Reincarnation}} in-between. [[Manga/DragonBall It's complicated.]]) Not to be confused with the time [[FusionDance Piccolo fused with Nail]], a completely different and unrelated ([[IdenticalStranger though identical-looking]]) Namekian.
** The Buu saga liked to play with this. For starters, the FusionDance merges two fighters' personalities as well as their appearances. After that, Buu is absorbed by his [[EnemyWithout dark side]], but the new hybrid form is restrained from killing some people due to his good side's influence... ''[[KillEmAll Some]]'' [[KillEmAll people]].

* The goal of the Meta (a gestalt entity of AIs created as [[LiteralSplitPersonality Literal Split Personalities]]) in ''Machinima/RedVsBlue: Reconstruction'' is to reconstruct the original Alpha [=AI=] from which they were split off. According to WordOfGod, the first [=AI=] in the Meta (Sigma) intended to rebuild the Alpha with itself as the leader.

[[folder:Web Comics]]