Insanity

Insanity is a recurring theme in the Mega Man franchise, and, by extension, in X Chronicles. Many characters within the franchise exhibit or develop symptoms of mania or outright insanity and seek to cause great harm and destruction to others and the world for their cause. Though these individuals often start off good-willed and mean to help and benefit humanity or robot-kind, the amount of damage that will be inflicted by their plans heavily outweighs the positive changes, and so they must be stopped by others. Some individuals are driven to insanity instead for something that has happened to them or someone they care about while others are driven to prove their own self-worth but go to extreme measures to do so. The line between evil and insanity is often blurred and the audience is left to wonder how much of a character's actions are due to evil intentions, and thus blameworthy, and how much are the result of a dysfunctional psychology or external influences overriding the character's will.

Characters that can be said to be insane

 * By the time X Chronicles started, Dr. Wily (in his Serges body) was long gone into his insanity. He created Zero and the virus just to prove that his genius is superior to Dr. Light's, not taking into account that a sentient virus would crave destruction. He currently is so insane, he didn't even seem to notice that X and the original Mega Man are two different robots. (Although X is aware he's not the first Mega Man, as Wily confounding X for Mega Man is what allows X to figure out Serges is Wily.)
 * The virus is extremely psychotic, growing more and more insane with each defeat at X's hands: he corrupted Sigma, Dr. Doppler and many other Maverick Hunters, killed and ruined the lives of millions of humans and Reploids, and staged a civil war. X claims that the virus enjoys nothing more than he, the virus, winning, implying that the virus relishes in the agony he causes.
 * Zero, upon first waking up, was completely insane due to the virus being in his programming, seemingly not even having the ability to talk beyond manic laughter and rage-filled yells. Zero in this form was able to wipe out Garma's Unit and beat Sigma into submission before a W formed on his head and caused him to cringe in pain. After his defeat at Sigma's hands, Zero's personality flipped completely and he became a Maverick Hunter.
 * Mega Man X, although more stable than most Reploids and despite the fact he's said to have unlimited potential, he does have a limit: he can't stand the deaths of innocents and of his friends, as implied by Chill Penguin. After Zero's sacrifice in Rise of Sigma, X snapped and completely destroyed Vile. Although he didn't snap again until the end of the Repliforce incident, he comes rather close when fighting Magma Dragoon. After the Repliforce incident, he stated to his friends he will pretend to be a Maverick, in order to play the virus for a fool.
 * Vile suffers from a short circuit in his electronic brain, causing him to be reckless and needlessly violent. Even though he was a Maverick Hunter, Vile's aggressive nature got him branded as a Maverick due to how much of a danger he was to himself and everyone around him. When Sigma became a Maverick and initiated a revolution against humanity, Vile joined the movement to prove his strength. He was destroyed by X in Rise of Sigma, but later rebuilt and upgraded by Dr. Doppler in Doppler Effect. Upon being resurrected by the doctor, Vile found that the only thing he could think of was exacting his revenge on X, and he broke free from Doppler's control to pursue X on his own, only to be defeated again and incarcerated.
 * Double was shown to have a split personality befitting his two forms. While his rotund first form is shown to be well-mannered and meek, his second form was shown to be very psychotic and sadistic, taking noticeable pleasure in slaughtering his fellow Maverick Hunters upon being ordered to do so by Teagan, and even when defeated by X showed absolutely no remorse for his actions.
 * Iris has a fragile soul, as, during the Repliforce incident, she snapped after her own brother, Colonel, called her a traitor. Ashamed, she fused her power core with an odd creation of Gate's, which would have resulted in her death if X wouldn't have connected her to Zero's power core.
 * Gate's situation is uncertain, as we don't know if his backstory is similar to the one from his games.
 * Practically all viral Mavericks are in the same situation: they originally had a firm grip on their sanity, but they lost it after they were infected and X needed to save them from themselves. Some, however, also have something darker behind the virus:
 * Chill Penguin snapped after losing seven partners.
 * No human cared for Launch Octopus, with the sole exceptions of a girl named Jessica and her grandfather.
 * Boomer Kuwanger was abused by humanity, until Dr. Cain made them stop. While at it, Gravity Beetle was traumatized both by the abuse suffered by Kuwanger and the fact Kuwanger dies in Rise of Sigma (or so did Beetle originally thought).