Villain Team Up / Anime & Manga

• Chapter 157 / Episode 42 of Assassination Classroom shows us that Shiro has joined forces with the God of Death.
• Defied in Bleach: Yhwach made a point about visiting the last major villain, Aizen, in his prison cell to offer him to join his army. Aizen refused, presumably because his delusions of godhood left him too proud to become anyone's henchman, even if the person making the offer was capable of one-shotting an enemy that Aizen wasn't willing to approach without major preparations. Instead, Aizen ends up helping the heroes defeat Yhwach.
• In the Devilman versus Getter Robo Crossover, the demons team up with the Dinosaur Empire.
• Dragon Ball:
  • In some filler episodes of Dragon Ball Z Cell, Frieza, and his Quirky Miniboss Squad teamed up to take over Hell. They got along surprisingly well.
  • In Dragon Ball GT practically everyone the protagonists had ever killed teamed up in Hell to try to get revenge, though most of them were just used as distractions until Dr. Myuu and Dr. Gero could create Super Android 17.
  • In the movie Fusion Reborn the villains escaped from Hell as a result of Janemba’s reality warping. However, nearly all of them were reduced to cameos and the only one of them who got any real screentime was Frieza, who would end up being quickly killed by Gohan.
• In the episode of Inuyasha entitled 'Naraku and Sesshomaru Join Forces'...Take a wild guess.
• JoJo's Bizarre Adventure: Stardust Crusaders: Towards the end of the Part, two past villains of the week team up when Hol Horse kidnaps Boingo to help him kill the heroes, which the latter goes along with. Both characters were already used to working in a pair but each had their old partner taken out of the picture (J. Geil killed and Oingo hospitalized), making teaming up a good proposition for the both of them (Hol Horse's M.O. is only working with a partner.) However, both are Ineffectual Sympathetic Villains, so they end up taking themselves out, without the heroes even knowing a team-up happened.
• In the Mazinger Z versus Devilman feature, Dr. Hell and the demons collaborate to take down Kouji Kabuto and Devilman. It may be subverted, since Hell used a mind-control device to enslave the demons, and he was mainly interested on taking down Mazinger Z (he only sent some demons and Mechanical Beasts against Devilman because the demons warned him he would interfere).
• Malik/Marik and Yami Bakura from Yu-Gi-Oh! Battle City arc.
• In the Magic Knight Rayearth anime, Alcyone proposes this with Ascot (they're both minions of the Big Bad, but they work independently). He follows her lead in good faith, but she tricks him into giving one of his beloved creatures a Deadly Upgrade and then freezes him solid when he gets upset, laughing over his gullibility.
• Naruto:
  • Kabuto and Tobi end up doing this.
  • Kabuto takes it a step further with his mass resurrection jutsu of almost every big name character to ever die in the series^note The former Hokages were all unavailable because their souls were sealed in the Shinigami's stomach, and Jiraiya's body was so deep underwater that Kabuto was unable to recover a DNA sample for the jutsu. And Orochimaru wasn't completely dead thanks to the cursed seals. At least in the anime, literally every other relevant character who had died up to that point in the series was revived as part of Kabuto's zombie army., forcing them to work together against the protagonists. They are mostly villains, but they also include some heroes who are implanted with seals that force them to obey Kabuto.
• The final arc of Tiger & Bunny saw a Villain Team Up of Big Bad Maverick and villain from one of the earlier episodes, Doctor Rotwang. They got along very well, despite that one of them was NEXT-hater and the other was secretly a NEXT himself until they were at the verge of Disney Villain Death, with Rotwang begging Maverick to save him, only for him to reveal he is a NEXT and kick him in the face.
• In One Piece, "pirate alliances" are commonplace, and while they don't always involve villains (for example, Luffy's Straw Hat Pirates form an alliance with Trafalgar Law's Heart Pirates), evil pirates do in fact outnumber good ones and such alliances are usually villain team-ups. Most notably, the Wano arc introduces an alliance between its Arc Villain Kaido and the previous Arc Villain Big Mom, the two most powerful foes the heroes have faced to date. Notably, Kaido and Big Mom have considerable animosity for each other as well, and openly agree to fight a Duel to the Death after they've killed all their other enemies.
  • The earliest example was in the Loguetown arc, when Alvida and Buggy teamed up to get revenge on Luffy. This alliance has to date remained in effect even after the Time Skip, Alvida still remaining a key officer in Buggy's expanded crew.
  • During the Marineford arc, Blackbeard breaks numerous other powerful pirates out of Impel Down and recruits them.
• This happened quite frequently in early Pretty Cure All Stars movies- the second movie, for instance, sees villains from the first four seasons revived and teaming up, while the third saw all the previous movie villains teaming up.
• Patlabor: The TV Series: Episode 42, titled appropriately enough "The Men Who Returned", features 3 previous villains teaming up and forming a Terrible Trio.

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