This is the trademark tactic for Dr. Wily and Sigma in the Mega Man series.
- Wily pretended to reform in Mega Man 3, and in all subsequent main series games except Mega Man 7, Mega Man 8, and Mega Man 11, he turns out to be using the initial villain or some other phenomenon as a decoy. He also does it in Mega Man V for the Game Boy with the Stardroids, though in a bit of a twist, he is not the final boss of the game. Amusingly, Mega Man 9 and Mega Man 10 don't even try to hide that he's the final boss in those games, as the achievement for beating each game is "Whomp Wily!"
- Super Adventure Rockman is also a rare exception, where Wily sets up the Big Bad but loses control of it, a la Mega Man V.
- A lot of fan games that have Wily as the Big Bad of the game, like Mega Man Unlimited and Mega Man Super Fighting Robot, also go this route, though the latter has Mega Man see this trope coming.
- In the Mega Man X games, Sigma hijacks all the main villains from Mega Man X2 onward, to the point it's a twist that he isn't the Big Bad of Mega Man X8 (though the plot point of New Generation Reploids having Sigma's DNA in their Copy Chips as well as Lumine more or less carrying out Sigma's plans means he's instead a Greater-Scope Villain). This gets lampshaded in Mega Man X4 when Split Mushroom responds to a demand to reveal the mastermind behind the game's plot with the meme-tastic "Take a wild guess", after which his lifebar, carrying Sigma's logo, appears, unlike members of Repliforce. note It's also subverted in Mega Man X6, where the Big Bad was not Sigma; it was Gate, and Gate resurrected Sigma to use him to destroy X, but Sigma Came Back Wrong (due to stretching himself too thin when he spread the Sigma Virus over the entire planet) and was obviously not the controlling force behind the plot. Even so, despite being the Reploid equivalent of a Revenant Zombie and only slowly regaining coherence as time passed, Sigma drops this line upon revealing himself and offing Gate in the process.Sigma: Oh please. I did not die. Nor did I need your help! Now get lost!
- Mega Man X5 reveals that the Maverick Virus was originally carried by Zero before it was transferred to and bonded with Sigma, thus meaning Wily hijacked the entire X series, because he was the creator of Zero and the original "Zero Virus" that turned Sigma evil. X5 was originally intended to be the final game of the X series, and Word of God has stated that yes, Wily was still alive and was working with Sigma during the game.
- Due to his hand in the creation of the Maverick Virus and Zero, Wily also indirectly set up the events of the Mega Man Zero series that acts as a continuation of the X series, so he could be considered to have hijacked that too, especially when Dr. Weil, the Big Bad of the Zero series, uses a robot (Zero's original body, specifically) that Wily built.
- Dr. Weil himself pulls this off. The first two Zero games each have different villains, but ultimately Weil (who only first appears in the third game) is the Greater-Scope Villain for both. He even resurrects one of the previous main villains (Copy X) as a Puppet King and Disc-One Final Boss, if only to further his plans.
- Finally, the Mega Man ZX series that continues the Zero series, the original Biometal W is a part of the Ragnarok space station from Zero 4 and has Weil's consciousness possessing it, driving other Reploids Maverick. It's also implied to have driven the major antagonists of the games into Brainwashed and Crazy territory by compelling them to carry out its will. Curiously, Master Albert, the Big Bad of ZX Advent and the person who orchestrated the "Game of Destiny" that drives both titles, states that he is the one in control of Model W and not the other way around. With the ZX series Left Hanging following Albert's demise, it's unknown if he would've been able to back up his claims, though he does show a far greater understanding and application of Model W's powers compared to Serpent, the main villain of the first ZX.
- In the Mega Man Battle Network games (which are an Alternate Timeline from the rest of the series), Wily hijacks 2 when the main villain of that game reveals in the third he was working under orders from Wily. 4 and 5 do not have him, making it actually effective when he appears in 6 and reveals his Evil Plan. However, the villain of 4 and 5 is the organization Nebula, led by Wily's son.
- Even X-series fan games get in on it. Mega Man X: Mavericks continues the tradtion of Sigma being behind everything, so there's no point in spoilering it. That being said...
- In the third game, Sigma is working with Dr. Weil. Sigma ends up getting taken out and Dr. Weil becomes the sole bad guy for the rest of the game. This trope kicks in when after the final battle, we find that Dr. Weil had been possessed...
- In the fourth game, X is so sure that Sigma is behind Gate's plans that he already starts asking the bosses about it before reaching the fortress. He's right, of course, but Sigma was only brought back thanks to the Stardroids, who were under the leadership of the real bad guy responsible for everything: Dr. Wily.
