History ThatOneBoss / MegaMan

!!Mega Man and Bass
* ''Mega Man and Bass'' is notorious for Dynamo Man, who likes to hop into a recharging rig in mid-battle. By the time you break it, he'll have regained at least a third of his HP (and he'll happily refill completely if you take long enough).
** Just as bad as Dynamoman is Burnerman, who resides at the end of ThatOneLevel, and has several attacks that deal a lot of damage as well as one that holds you in place as he has his way with you. His Wave Burner is also capable of deflecting shots, and he likes to back you into a corner with it. Fighting him with his weakness, Coldman's Ice Wall, he becomes somewhat of a PuzzleBoss, having to use the Wall to push him into the spikes on either side of his arena. Thing is, there are only certain frames that he's vulnerable to this, any other time and he'll bust right through it, and you've wasted your ammo. If you mess up too many times, it's easy to run out of ammo, and be forced to go through his agonizing stage all over again.

!!Mega Man Powered Up

[[Game/MegaMan http://static.tvtropes.org/pmwiki/pub/images/airman_taosenai_nekokan.jpg]]

MegaMan stands as a shining example of classic NintendoHard. These guys are the reason why. It doesn't matter if you've got the [[GoodBadBugs select trick]] or a [[MegamanBattleNetwork folder full]] of [[LimitBreak Program advances]], these mechanized murder Masters are coming for you.

* It should be noted that the ''Game/MegaMan Anniversay Collection'' features an easy mode that covers the first seven games. The NES games benefit with Megaman's defensive and specials weapon power being upped by 50%, buster shots do an extra unit of damage, while Megaman 7 doubles the power of every weapon. The bosses can still be a pain in the ass though.

* Elecman is possibly the hardest boss to kill with only your pea shooter in ''any'' Megaman game if you don't know [[http://www.youtube.com/watch?v=4FMCwvh60tM the cheap way to beat him]]. He runs around the arena like he's on crack, throws nearly impossible to dodge lightning bolts at you and ''can kill you in three hits!'' Granted he's very weak to the Rolling Cutter (Cutman's weapon), but if you didn't quite figure out that bosses have weaknesses...

** The Devil returns as the Shadow Devil, serving as the first Zero Virus Stage boss in ''MegaManX 5''! This one has an alternate form based on the Mega Man 6 Wily Machine that can instakill! Not only that, it's at the end of the ScrappyLevel!

** Then the Rainbow Devil shows up in ''MegaManZero''. It's just as cheap as previous models. It has an especially annoying attack where it bounces around the room, splits into two parts, then into four before finally reforming. It also has a punch attack that crosses nearly half the arena and a projectile attack that makes nearly the entire ground a danger zone. Good times. Thankfully, the redux in ''Zero 2'' is actually somewhat easier.

* The final boss of ''7'' also fits here. He is definitely overly hard by the standards of final bosses for the Mega Man series. His weakness, the Wild Coil, is (as per the tradition) difficult to hit him with. His main attack is shooting four elementally charged orbs in your direction, then [[{{Roboteching}} they stop in mid-flight to adjust their path]]. And they ''hurt''. Fortunately, he's at least damaged by some other, easier to hit with weapons, such as Freeze Cracker. WordOfGod says that even the developers found this one impossible without E-Tank usage. Even has some [[LampshadeHanging]], in which Megaman attempts to kill Dr. Wily following the battle.

* In ''MegaManPoweredUp'', it's CWU-01P, especially when playing as [[JokeCharacter Rock/Mega]]. His main way of hurting you is CollisionDamage. Sounds easy, right? WRONG! At least on the aptly-named Hard Mode, he's damned fast. And as the aforementioned JokeCharacter, you can't hurt him without getting right in his face and kicking him enough to first get rid of his bubble shield, then once more to actually cause damage. Oh, and just for good measure, he does also have another attack -- a [[FrickinLaserBeams frickin' laser beam!]]

* If you collect all of Zero's parts from the X-Hunters in MegaManX 2, then you'll be able to skip the battle against Zero at the end of the game. If you don't, you're in trouble at the end of the game before you battle Sigma. The only weapon that really hurts him- the Speed Burner- is hard to hit him with, and his attacks are hard to dodge. And after you've beaten him (probably draining all your Sub-Tanks in the process), you still have to fight Sigma. The moral of the story is to get all of his parts, no matter how hard they are to get early in the game.

* If you thought Storm Eagle was bad, The Skiver/Spiral Pegacion from MegaManX 5 is a nightmare, boasting the same sort of attacks, but all vastly more difficult, coming from all directions at high speeds. Oh, and making him a standout from every other boss in the entire series, he does not have an actual weakness to a specific power. Instead, he can be frozen with the timestop power, which doesn't last long enough to punch off a decent portion of his health.

[[folder: Mega Man Legends]]

* The three cerebus breed reaverbots in the Clozure Woods Sub-gate. Those things are NASTY if you're not CrazyPrepared for them. The all attack you at once and they are FAST. Their primary attack is jumping at you, which knocks MegaMan down and is possibly also a CameraScrew if you land right. Their other attack is to BREATHE FIRE, which instantly depletes your life meter's shield so you can take MORE damage from their jump attack.

!!Mega Man Battle Network 2
* MegaManBattleNetwork 2 had Quickman.EXE. The name alone should key you in to how annoying he's going to be. He is invincible at all times except during his attack frames, moves like a spastic monkey on crack, and his attacks are irritating to dodge, because [[{{ShapedLikeItself}} Quick Boomerangs are really, REALLY fast moving]] It doesn't help that he's the second boss of the game, the first boss was a complete chump, and the next boss AFTER him isn't exactly threatening either, so he's not even really a WakeUpCallBoss... Worse yet, it's ''entirely'' possible for the game to be UnwinnableByMistake here, as you can't leave his area (either to recover HP or improve your moveset) once you enter (but nothing stops saving...)

** To elaborate, he never leaves the back row and the center tile on his side is a hole from which spout an infinite number of bubbles, which block shots and home in on you, always moving into your row so as to block your line of fire at Bubbleman. Since they're limited by number on screen if you stand there shooting them they'll just spawn faster. Meanwhile Bubbleman is using his ''own'' attacks on poor distracted Megaman. Luckily the electric-element first boss has a megachip that can hit and stun Bubbleman no matter where he hides.

* [[http://megaman.wikia.com/wiki/KingMan.EXE Kingman]] is the second hardest boss in MegaManBattleNetwork 3. He hides in the far back row while his nearly invincible, regenerating chess pieces attack you and block your spaces. If that wasn't annoying enough, if you stay in the back row (the easiest way to avoid his chess pieces), Kingman has a "plan B" attack, where he summons some new chess pieces and ''permanently steals an entire row of your area''. Not even Bass's auras can compare to this guy's cheapness.

* ''MegaManNetworkTransmission'' had Brightman.EXE, the first boss to put up shields to your attacks. Whereas the previous bosses were dodging and slapping the boss hard enough before they got you, Brightman will ''murder'' you if you try the tactics that worked on the previous bosses and indeed, some of the other bosses you can fight at the same time. And the bosses get craftier, more agile or with more invincibility shielding from there, making Brightman a WakeUpCallBoss.

* The Spidrill miniboss in ''MegaManZX Advent''! It breaks the floor (which, in addition to removing a quarter of your standing space, can affect whether or not you unlock a vital checkpoint so that you ''never have to do that again''), the walls have got spikes on, it summons miniatures of itself, and it has an irritating tendency to spam a move that spins its legs around. The upgraded Spidrill Neo fight in the Quarry is comparatively easy for nixing the first two aspects and coming right after you unlock [[GameBreaker Model ZX]].

* The Infinity bosses from ''MegamanStarForce 2'', particularly Cancer. They managed to take one of the (arguably) [[BreatherBoss easiest bosses]] in the game, and [[TookALevelInBadass upgrade him]] to have absurd speed and 2800 HP (!). On top of that, his claw attack is now so fast that it's basically an unblockable 200 damage unless you have an Invisible on you.

[[/folder]]

** Note that the Japanese original of the game (which spawned this particular bit of MemeticMutation) only has hard mode. This means you do half damage to all bosses, and some enemies too. The US version was made easier be default, and Air Man is affected by this. While you can pretty much ignore dodging on the American version on normal, you actually have to [[WakeUpCallBoss learn to play]] on the Japanese version (hard mode in the US). And one of his attack patterns cannot be dodged...

* Heatnix's miniboss, with Zero at least, is cake if you've beaten Mijinion first. Slap it with the Giga Attack twice and it's gone. The real bastard is Gate. Invulnerable to all your attacks, so you have to turn his back on him, and tends to fly right into you. His attacks are ALSO hard to turn back on them, since they need to be level with him, and then hit him in the face as they break from damage. The most damning part of the fight is the arena. There is no floor, so you're liable to fall to your death more often than not. The only good thing about this battle is that you freeze in place when Gate runs out of health, so there's no risk of falling to your death after beating him senseless.

* The Bosspider, due to the speed she moves at, the difficulty of quickly figuring out where the boss will end up depending on what pole she appears on and where the pegs she moves along appear and the timing needed to hit before she regains its invincibility. And then she TurnsRed.

** Oh, and Violen is the worst of the three fights you have to do to get the Zero Parts, considering he liked the idea of Armadillo's invincible attacks, but decided to make them even less predictable.

Please keep in mind that if there's an easy method to take out a boss, they're not this trope. Remember as well that WeAreNotGameFaqs, your example shouldn't read, "Unless you do.." or "But if you have.." ThatOneBoss is the guy who kicks your ass even with a trick. This being Mega Man, every boss has a weapon that they're weak to. If that weapon turns out to be impossibly frustrating to use, that boss probably belongs here.

* Bass, from any of the ''MegaManBattleNetwork'' games. Most of his attacks cover the field in hard-to-dodge projectiles, and he always has a shield that absorbs 200 damage for him. His upgraded versions in the later games add more to his bag of tricks: his shield requires more damage to drop and he usually has an attack that limits your movement as well.
** The worst part about Bass is that he is in the part of the game that requires that you know what you are doing with your chip folder. The difference in difficulty between the end boss and the bonus parts of the games is an enormous step up from "Throwing a bunch of good chips into a folder" to "God forbid you have more than two chip codes you worthless sack of junk data". It's a disturbingly different level of gameplay.

* Sirius. Arguably the hardest BonusBoss in all of Star Force, beating out Apollo and Cancer Bubble IF. Absurd amount of health? Check. Unable to knock him out of any attacks? Check. He throws up shields at the start that he can fire lasers through, but that's not the worst part. His signature move is a laser that hits the entire field and breaks the floor, leaving you with no room to move, but '''THAT'S''' not the worst part. The worst part is an attack in which he detaches his wings, which start shooting elemental lasers ''that break guards, are absolutely unavoidable, and are ungodly fast.'' In addition, since he has 4 wings on 3 columns, one of the attacks will be double-element. And god help you if you're knocked out of a Noise.

* If you thought Storm Eagle was bad, The Skiver/Spiral Pegacion from MegaManX 5 is a nightmare, boasting the same sort of attacks, but all vastly more difficult, coming from all directions at high speeds.

* [[PlayingWithFire Model F]]'s second boss: ''Flammole''. It's not fighting him that's difficult, it's his [[AttackItsWeakPoint weak]][[AvertedTrope point]]. (In this game, hitting a bosses weakpoint basically means it weakens the [[MegaManning form that you get for beating them]]). It also [[RankInflation decreases the rank]] that you get for beating the boss (highest is level 4, lowest is [[CaptainObvious 1]]) The problem here is, his weakpoints are his '''[[PrecisionFStrike Fucking]] ARMS'''. [[http://www.youtube.com/watch?v=Qf6GS4OBEOQ See him in action]]. Imagine yourself, trying to [[RankInflation Level 4 Victory]] this boss. Now, imagine yourself throwing your [[NintendoDS DS]] across the room trying to kill him while avoiding those '''[[ClusterFBomb Fucking]] ARMS'''. After beating him, you can go to the base and [[TheDevTeamThinksOfEverything fix your form]] (for a fee) since '''[[WhatTheHellPlayer YOU]]''' weakened it. But if you're playing [[NintendoHard Hard]] Mode, the fee to fix your form gets raised to a '''[[AdamSmithHatesYourGuts RIDICULOUS]]''' [[BeyondTheImpossible price]]. So you have no choice but to avoid those '''[[RunningGag FUCKING ARMS]]''' and spend over [[MemeticMutation 9000]] dollars replacing all the [[NintendoDS DS']] that you threw.

* 2 also had Napalmman [[RecurringBoss V3]]. He has [[MarathonBoss 2000 HP]], ''actually has moves that are difficult to dodge'', and they pack ''[[{{Understatement}} quite a punch]]''. CrystalDragonJesus help you if you have a [[ElementalRockPaperScissors Wood Style]].

* [[PlayingWithFire Model F]]'s second boss: ''Flammole''. It's not fighting him that's difficult, it's his [[AttackItsWeakPoint weak]][[AvertedTrope point]]. (In this game, hitting a bosses weakpoint basically means it weakens the [[MegaManning form that you get for beating them]]). The problem here is, his weakpoints are his '''[[PrecisionFStrike Fucking]] ARMS'''. [[http://www.youtube.com/watch?v=Qf6GS4OBEOQ See him in action]]. Imagine yourself, trying to [[RankInflation Level 4 Victory]] this boss. Now imagine yourself throwing your DS across the room trying to kill him while avoiding those '''[[ClusterFBomb Fucking]] ARMS'''. After beating him, you can go to the base and [[TheDevTeamThinksOfEverything fix your form]] (for a fee) since '''[[WhatTheHellPlayer YOU]]''' weakened it. But if you're playing [[NintendoHard Hard]] Mode, the fee to fix your form gets raised to a '''[[AdamSmithHatesYourGuts RIDICULOUS]]''' [[BeyondTheImpossible price]]. So you have no choice but to avoid those '''[[RunningGag FUCKING ARMS]]''' and spend over [[MemeticMutation 9000]] dollars replacing all the DS' that you threw.

* [[PlayingWithFire Model F]]'s second boss: ''Flammole''. It's not fighting him that's difficult it's his [[AttackItsWeakPoint weak]][[AvertedTrope point]]. (In this game, hitting a bosses weakpoint basically means it weakens the [[MegaManning form that you get for beating them]]. The problem here is, his weakpoints are his '''[[PrecisionFStrike Fucking]] ARMS'''. [[http://www.youtube.com/watch?v=Qf6GS4OBEOQ See him in action]]. Imagine yourself, trying to [[RankInflation Level 4 Victory]] this boss. Now imagine yourself throwing your DS across the room trying to kill him while avoiding those '''[[ClusterFBomb Fucking]] ARMS'''. After beating him, you can go to the base and [[TheDevTeamThinksOfEverything fix your form]] (for a fee) since '''[[WhatTheHellPlayer YOU]]''' weakened it. But if you're playing [[NintendoHard Hard]] Mode, the fee to fix your form gets raised to a '''[[AdamSmithHatesYourGuts RIDICULOUS]]''' [[BeyondTheImpossible price]]. So you have no choice but to avoid those '''[[RunningGag FUCKING ARMS]]''' and spend over [[MemeticMutation 9000]] dollars replacing all the DS' that you threw.

* Bamboo Pandamonium. He's big enough that you can't get behind him without taking a hit, and has attacks that take up big chunks of the screen. Also, his desperation attack hits like a train and comes with virtually no warning. It's more bearable with the Ride Armor...What's that? [[GuideDangIt You didn't know that you could take it with you?]] Too bad!

* And then there is Red. If you don't have Zero, good luck to you. You have to target Red from a distance. Since the camera enjoys screwing you, this becomes a problem. Dodging his attacks is problematic because you're not fighting on solid ground. You're fighting on platforms with a hole in between each one. Fall and you die. Get hit while jumping and you will die. He constantly teleports around on those platforms and there is no way to predict where he will end up. The only way to finish the fight quickly is to use Zero and take Collision damage while slashing him.

** Making it worse is that you can't revisit stages. Couldn't find Subtanks or enough E-Crystals to upgrade youe Cyber Elf? Too bad! Also, he appears after you've beaten 4 out of 8 stages. He also has no weaknesses. Some people were left with no choice but to ''restart the game''.

** Chronoforce on Expert starts the fight with Time Bomb, and it never wears off, so he's always in turbo speed. What's more, you know that spreading icicle move he does that you were able to jump between on Normal? Now he shoots two sets of icicles, the second set covering all the angles the first doesn't, making a roughly 90-degree arc that's really tough to avoid whether you try jumping between them or dashing underneath Chronoforce to get past them entirely. And may God help you if you haven't figured out the trick to dodging his attack where he shoots a whole volley of potentially exploding icicles at you from the background, then ''rewinds them to hit you again''.

* The Infinity bosses from ''MegamanStarForce 2'', particularly Cancer. They managed to take one of the (arguably) [[BreatherBoss easiest bosses]] in the game, and [[TookALevelInBadass upgrade him]] to have absurd speed and 2800 HP (!). On top of that, his claw attack is now so fast that it's basically an unblockable 200 damage unless you have an Invisible or too.

* Shadow Man. He is insanely fast, and his attacks are very hard to dodge. On top of this, the only weapon that can hit Shadow Man effectively, the Top Spin, has to be used at very close range, and its weapon reserve energy drops like a stone when you are using it while in direct contact with Shadow Man. What tends to happen is that if you try attacking directly with Top Spin, ALL of its weapon power can get drained when you land your first hit. Then Shadow Man still has 75% health and you have no Top Spin power left. Good luck hitting him with the Arm Cannon, and even if you know his pattern, he is still very difficult to beat. The right way to beat him is not to charge into him while using Top Spin, but to let him come to use and use the Top Spin to "graze" him in 4 hits. Even with this technique, he is still very difficult to beat.

* The {{Sub Boss}} of Blaze Heatnix's stage. Which you fight multiple times over the course of the entire stage. The worst offender is the part where you fight it while forced-scrolling upwards on very small footholds. Which the sub-boss is bigger than. It doesn't help that there's insta-kill lava ''covering half the fucking screen.''

** From the same game, Sigma and Kaiser Sigma. Sigma's swapped out his Z-Saber and WolverineClaws for a CaptainAmerica-esque shield, which [[LuckilyMyShieldWillProtectMe defends him from all attacks as long as it's bared]]. His main attack consists of spraying fireballs all over the place, which have an unpredictable pattern and do ''huge'' damage. They can be avoided by air-dashing to the wall Sigma's adjacent to, so of course he begins throwing his shield to knock you out of the sky. And when you do bring him down, you get to face Kaiser Sigma, who takes up a quarter of the screen, fills another quarter of it with floating mines, has a weak spot about the size of a pinhead, and keeps his back to you for half the match. Oh, and when he's dead, you have to do an escape segment with rising lava eager to nip away your last few bars of health. He may be the final boss, but he's considered to be easily the worst of all the SNES games.

* The final boss of ''7'' also fits here. He is definitely overly hard by the standards of final bosses for the Mega Man series. His weakness, the Wild Coil, is (as per the tradition) difficult to hit him with. His main attack is shooting four elementally charged orbs in your direction, then [[{{Roboteching}} they stop in mid-flight to adjust their path]]. And they ''hurt''. Fortunately, he's at least damaged by some other, easier to hit with weapons, such as Freeze Cracker. WordOfGod says that even the developers found this one impossible without E-Tank usage.

* Quick Man from ''Game/MegaMan 2'', if not because his stage is "ThatOneLevel" It's because he is incredibly fast, and does almost 1/3 of your life bar with one CollisionDamage! Oh, and there is an attack that can take half his life in one shot, but odds are you will probably need it to get past the almost impossible laser barrage right before his door!
* Doc Robot from '3'' takes the abilities of ALL the Robot Masters from Mega Man 2 (You fight 2 per level, and they make you play through the four harder stages revamped to be harder). If you thought Dodging Wood Man's swirling leaves was bad before, try it when they are even larger! Try fighting Crash Man without an attack that can shoot up! TRY FIGHTING A LARGER, FASTER QUICK MAN! Geez, and people think Gemini Man is bad...
** Oh, and since it's ''Mega Man 3'', you now have to try and figure out which weapons the Mega Man 2 robots are weak against, all over again. Almost none of them are intuitive either.
** Bonus points for the Wood Man version, as the Leaf Shield has both larger leaves and larger shield radius -- large enough that you almost need Rush Coil to get over it (which consequently smacks you into the leaves coming from above).
*** Further bonus because, even when you ''do'' figure out their weakness, they aren't as effective as their weakness was in ''Mega Man 2'' (nothing can break through the Leaf Shield, for example).

* The Yellow Devil from ''1''. Many gamers had lost a good chunk of their childhood trying to get past this shining example of NintendoHard. Unless they cheated.
** The worst part about the Gamecube version ''Anniversary Collection'' is that the glitch that makes the Yellow Devil easy to beat was drastically changed (the timing was changed to make it less effective if you knew the change, worthless if you didn't), thereby making the fight that much more difficult.
** The Yellow Devil makes an appearance as the SECOND guardian of Wily's fortress in ''3'',(although he's much easier there, even before considering that you have storable E-tanks) and a goo version called the Green Devil appears in ''8'', too.
** The Devil returns as the Shadow Devil, serving as the first Zero Virus Stage boss in ''MegaManX 5''! This one has an alternate form based on the Mega Man 6 Wily Machine that can instakill! Not only that, it's at the end of the ScrappyLevel!
** They did have a devil in 9 too. ''Two of them at the same time''. Both the yellow and green devils sent blocks of each other right at you at the same time. The pattern is actually easier this time, however, but the core flying out to switch blobs in the middle of it all makes it a little annoying. Inti Creates, you clever bastards...Fortunately, the pause-glitch works on it.
** And 10 gave us a new model: the ''Block Devil''. Imagine, if you will, an unholy union between the Pico Pico Master (2nd fortress boss from ''2'') and the Devils' penchant on splitting and reuniting in definite patterns, throwing in a weakpoint that stays on screen only 1/3 of the battle and ''a bottomless pit'' that becomes a KaizoTrap if you happen to defeat the boss standing on/over a purple block. Oh, and his weakness involves one of the most awkward weapons in the series!
** Then the Rainbow Devil shows up in ''MegaManZero''. It's just as cheap as previous models. It has an especially annoying attack where it bounces around the room, splits into two parts, then into four before finally reforming. It also has a punch attack that crosses nearly half the arena and a projectile attack that makes nearly the entire ground a danger zone. Good times. Thankfully, the redux in ''Zero 2'' is actually somewhat easier.
** And there was also Dark Moon, the Devil-type boss in ''Mega Man V'' for the Gameboy. He's hell to beat with his own weakness, the Photon Missile, and his separation attacks, the top two rows would bounce down in order to try to kill you.

* Also in ''1'' is Elecman, possibly the hardest boss to kill with only your pea shooter in ''any'' Megaman game if you don't know [[http://www.youtube.com/watch?v=4FMCwvh60tM the cheap way to beat him]]. He runs around the arena like he's on crack, throws nearly impossible to dodge lightning bolts at you and ''can kill you in three hits!'' Granted he's very weak to the Rolling Cutter (Cutman's weapon), but if you didn't quite figure out that bosses have weaknesses...
* The Wily Dragon in ''2''. Someone even wrote a a blog entry in which this boss fight was compared with a major real-life hangup. Made worse in ''Mega Man Anniversary Collection'', which removed [[GoodBadBugs an exploitable bug]] to make yourself invincible during the fight.
** While we're on the subject of ''Mega Man 2'', the other boss in Wily's Fortress that only has one way to damage it. Yes, that one. The turrets with blindingly fast shots from the walls heading straight for you every three seconds or so, AKA the Bluebeam Trap. And the kicker? You only have seven uses of the weapon maximum. Five to actually destroy them, and at least one to break barriers blocking the others. If you don't make clever use of Items and/or accidentally miss a shot or two then you will not be able to defeat this boss. And since you don't get energy refills after death you either need to take forever restocking energy off the few enemies or just game over entirely and restart the stage. There's a reason why practically every MM2 romhack out there, even the obscenely hard ones, generally make this boss ''easier''.

** The final boss of ''7'' also fits here. He is definitely overly hard by the standards of final bosses for the Mega Man series. His weakness, the Wild Coil, is (as per the tradition) difficult to hit him with. His main attack is shooting four elementally charged orbs in your direction, then [[{{Roboteching}} they stop in mid-flight to adjust their path]]. And they ''hurt''. Fortunately, he's at least damaged by some other, easier to hit with weapons, such as Freeze Cracker. WordOfGod says that even the developers found this one impossible without E-Tank usage.

* The Bosspider from ''MegaManX'', due to the speed she moves at, the difficulty of quickly figuring out where the boss will end up depending on what pole she appears on and where the pegs she moves along appear and the timing needed to hit before she regains its invincibility. And then she TurnsRed.
* Byte from ''Mega Man X3''. He's not all that difficult if you know what you're doing, but he uses an absolutely cheap and never-before-seen gimmick to utterly crush the unprepared. He throws a device on the wall that slowly repels X. He'll charge at you shortly after it attaches. If he hits you, he'll punch you into the ceiling, wait for you to fall, punch you into the opposite wall, and repeat the pattern. You cannot break free from the punch combo, and it's his one and only attack, so he can easily loop it until half your health bar is gone. He's too big to jump over, so you have to either execute a well-timed up air dash or dash-jump at the wall and use the split-second of hang time you have to dash-jump over him. Oh, and whenever he hits the wall, if you aren't in mid-air, you're on your butt, so you better have hopped over him before he hits.
** From the same game, Sigma and Kaiser Sigma. Sigma's swapped out his Z-Saber and WolverineClaws for a Captain America-esque shield, which defends him from all attacks as long as it's bared. His main attack consists of spraying fireballs all over the place, which have an unpredictable pattern and do ''huge'' damage. They can be avoided by air-dashing to the wall Sigma's adjacent to, so of course he begins throwing his shield to knock you out of the sky. And when you do bring him down, you get to face Kaiser Sigma, who takes up a quarter of the screen, fills another quarter of it with floating mines, has a weak spot about the size of a pinhead, and keeps his back to you for half the match. Oh, and when he's dead, you have to do an escape segment with rising lava eager to nip away your last few bars of health. He may be the final boss, but he's considered to be easily the worst of all the Snes games.

** DESU BORU!! Er... High Max. AKA 'Assclown'. "Hmm... What's this glowing crystal-like thing here? Oh, wow! Haven't been here before. Guess I can fight the main boss later. Huh? A door? Must be the main boss. Wait a minute... Pfft! This guy's no problem... Oh, wait. I don't have any weapons on me, and I need them. Like, at all. Time to kill myself!"
** The {{Sub Boss}} of Blaze Heatnix's stage. Which you fight multiple times over the course of the entire stage. The worst offender is the part where you fight it while forced-scrolling upwards on very small footholds. Which the sub-boss is bigger than. It doesn't help that there's insta-kill lava ''covering half the fucking screen.''
** Heatnix's miniboss, with Zero at least, is cake if you've beaten Mijinion first. Slap it with the Giga Attack twice and it's gone. The real bastard is Gate. Invulnerable to all your attacks, so you have to turn his back on him, and tends to fly right into you. His attacks are ALSO hard to turn back on them, since they need to be level with him, and then hit him in the face as they break from damage. The most damning part of the fight is the arena. There is no floor, so you're liable to fall to your death more often than not. The only good thing about this battle is that you freeze in place when Gate runs out of health, so there's no risk of falling to your death after beating him senseless.
** The Nightmare Mother(FUCKER!!)... Good God. On Normal difficulty, this boss fits her name to a damn tee. On Xtreme, she cranks this [[UpToEleven up to insane heights]]. Both cubes move at an accelerated speed even at full health and can change direction whenever they like, all while constantly firing projectiles at you until they stop. And if they do stop, you better hope the gods are smiling on you, since her attacks can be used by both eyes and combine sickeningly. Each eye can release shockwave-producing projectiles, raining fireballs, floating orbs that shoot lightning or even set the floor on fire. Two out of four of these attacks reduce your dodging room severely, and if they ever ''set the floor on fire AND shoot the lightning orbs'', then you better. Fucking. Pray.
* MegaManX 7. Let's go over them.
** Snipe Anteator. On paper, his weakness was the "Moving Wheel." In the game, you could barely get said weapon to hit him. Even if you could, it actually did LESS damage than a fully charged X-Buster. Translation: Just use X already. Oh wait, you have to unlock him first! On top of that, he doesn't have a hitstun animation, meaning that he can counter your attacks ''as they hit him''.
** Then there is Flame Hyenard. You had to damage a mech travelling over hot lava so you could get to him. This is easier said than done since the camera can screw you over. Then you fight Flame Hyenard. He splits himself into clones that shout [[MostAnnoyingSound "BURN! BURN TO THE GROUND!"]] The weapon he's weak against actually works, but if you're using X or Axl, you'll run out of ammo long before he is dead. And he has a ScrappyLevel to boot!
** And then there is Red. If you don't have Zero, good luck to you. You have to target Red from a distance. Since the camera enjoys screwing you, this becomes a problem. Dodging his attacks is problematic because you're not fighting on solid ground. You're fighting on platforms with a hole in between each one. Fall and you die. Get hit while jumping and you will die. He constantly teleports around on those platforms and there is no way to predict where he will end up. The only way to finish the fight quickly is to use Zero and take Collision damage while slashing him.
* If you collect all of Zero's parts from the X-Hunters in MegaManX 2, then you'll be able to skip the battle against Zero at the end of the game. If you don't, you're in trouble at the end of the game before you battle Sigma. The only weapon that really hurts him- the Speed Burner- is hard to hit him with, and his attacks are hard to dodge. And after you've beaten him (probably draining all your Sub-Tanks in the process), you still have to fight Sigma. The moral of the story is to get all of his parts, no matter how hard they are to get early in the game.
** Oh, and Violen is the worst of the three fights you have to do to get the Zero Parts, considering he liked the idea of Armadillo's invincible attacks, but decided to make them even less predictable.
* MegaManX has Storm Eagle. He is hard to hit in between attacks because he is about half way up the screen. When you fight him, there is a doom pit on either side. He has a number of hard to deal with attacks, but most of the time just flies around randomly, crashing into you.
** If you thought Storm Eagle was bad, The Skiver/Spiral Pegasus from MegaManX 5 is a nightmare, boasting the same sort of attacks, but all vastly more difficult, coming from all directions at high speeds.
** How could one forget Armored Armadillo? He has 3 strategies: guarding, bouncing off the walls and shooting his energy shots. He's invincible when ever he isn't shooting at you, as he will most likely block your attack. Guess what he decides to never do 90% of the time.
*** Now try fighting him on ''Maverick Hunter X'''s Hard Mode, where he picks up an attack where he bounces off the walls ''and'' fires off bullets in four directions. Even if you use the Electric Spark to take out his armor, it's still hellish.

* The worst part about Bass is that he is in the part of the game that requires that you know what you are doing with your chip folder. The difference in difficulty between the end boss and the bonus parts of the games is an enormous step up from "Throwing a bunch of good chips into a folder" to "God forbid you have more than two chip codes you worthless sack of junk data". It's a disturbingly different level of gameplay.
* Duo's Meteo Fist attack, and by extension Nebula Grey's dragon attack can easily make the fight unwinnable if you don't have Air Shoes or a Panel Return handy, since your field is cracked to the point where you can't dodge anything.
* Drill Man makes Battle Network 3 a nightmare. He has lower HP than most bosses, but that's because frontal attacks have no effect - his drill is always blocking frontal attacks, so you have to go ''around'' the drill with WideSwords and such. Only a handful of chips can bypass his drill, so good luck having one in advance when he appears!

* MegaManBattleNetwork 2 had Quickman.EXE. The name alone should key you in to how annoying he's going to be. He is invincible at all times except during his attack frames, moves like a spastic monkey on crack, and his attacks are irritating to dodge, because [[{{ShapedLikeItself}} Quick Boomerangs are really, REALLY fast moving]] It doesn't help that he's the second boss of the game, the first boss was a complete chump, and the next boss AFTER him isn't exactly threatening either, so he's not even really a WakeUpCallBoss... Worse yet, it's ''entirely'' possible for the game to be UnwinnableByMistake here, as you can't leave his area (either to recover HP or improve your moveset) once you enter (but nothing stops saving...)
* MegaManNetworkTransmission had Brightman.EXE, the first boss to put up shields to your attacks. Whereas the previous bosses were dodging and slapping the boss hard enough before they got you, Brightman will ''murder'' you if you try the tactics that worked on the previous bosses and indeed, some of the other bosses you can fight at the same time. And the bosses get craftier, more agile or with more invincibility shielding from there, making Brightman a WakeUpCallBoss.

* Aztec Falcon from ''MegaManZero'', the first mission boss from Zero is almost impossible the first time you fight him. You have no charge attack (unless you spent time grinding it out by going back to the Underground Base; if you're playing on Hard, you're screwed), he isn't vulnerable to combos, and the Z-Buster actually ''bounces off'' when the chance to shoot him presents itself.
** Phantom from the same game is spectacularly cheap compared to his fellow Guardians. Three of the Guardians have an elemental weakness which makes beating them fairly simple. Not Phantom. He's neutral, so it takes longer to kill him. Worse, the other Guardians can have most of their attacks interrupted. Only Phantom's dash attack can be interrupted. It is technically possible to interrupt his DopplegangerSpin technique with a charged blow, but for added cheapness Phantom will break the technique and strike you should you close in to attempt it. Speaking of the dash attack, he'll often do it until you hit him, and he charges to your position. If you don't hit him right off the bat, he'll get at least one hit in, maybe more if you don't score a knockback hit. Finally, his DesperationAttack makes him invisible, during which he'll throw kunai at you from random points on the screen. What's worse, he may potentially position himself above the reach of your weapons, or just plain ''above you''. To top this, he has a KaizoTrap ability in the second battle.
*** Phantom's caveat is that he's nearly impossible if you fight with the Z-Saber, but a total pussycat if you use the Buster. It locks him into his doppleganger attack and interrupts his dashes even at half-charge. On the other hand, he'll instantly counter at every opportunity if Zero tries to go samurai on him.
** Phoenix Magnion from ''Zero 2'' is plain ridiculous. He has an arena which spews fireballs from the floor, for starters. You can arrange it so the floor is blocked the first time you fight him, but not the second. What's worse, he ''dodges every attack''. He literally cannot be hit unless he's attacking. And when he dodges, he counterattacks with very wide-area abilities.
*** He's an Expy of M. Bison, which helps explain his difficulty (Of course). That huge fireball he "shoots" after dodging backwards is the Psycho Crusher. Hit the fireball (with him inside) with a thunder attack(It's your only chance of winning in Hard Mode!).
*** Also, Phoenix is purely reactive, which means that if Zero just closes the distance and waits for a second then he'll begin an attack without dodging or teleporting and leave himself wide open.
** Kuwagust Anchus in ''Zero 2'' on Hard Mode is just ''insane''! Not only is he really fast and powerful (two hits = dead, period), but he's the boss of ThatOneLevel! And he has an attack which can't be dodged, meaning you have to get him to change his flight path. And the only way to do this is to either shoot him with the buster enough times, which takes better timing than God to pull off, or deflect him with the Chain Rod. [[GuideDangIt As if you're just supposed to know this out of hand.]] And he'll keep using this attack till you die.
** Kraft from ''Zero 4'' is a nightmare to fight against. The grenades, the laser rifle that requires you to dash underneath it with split second timing, the giant knife that damages you as it throws you across the arena, the missiles, and the fact that he's one of the few bosses willing to get right directly up in your face on a non-scrolling single-screen battlefield are awful.

* The Infinity bosses from MegamanStarForce 2, particularly Cancer. They managed to take one of the (arguably) easiest bosses in the game, and upgrade him to have absurd speed and 2800 HP (!). On top of that, his claw attack is now so fast that it's basically an unblockable 200 damage unless you have an Invisible or too.

** Note that the Japanese original of the game only has hard mode. This means you do half damage to all bosses, and some enemies too. This makes a number of fights that are pathetically easy on the US version much more difficult, Air Man being one of them. While you can pretty much ignore dodging on the American version on normal, you actually have to dodge on the Japanese version. Except that one of his attack patterns cannot be dodged. Fortunately the odds are on your side...