Here’s a small blurb for the Protomen version of Zero (originally in the Megaman X series)
Wily, unbeknownst to Light or anyone else, sends out one of his Robot Masters to gather up the body of Light’s fallen friend, Joe. The helmet, Wily recognizes as the helm of the bot who killed Emily. Whether he considers this poetic justice or irony is unclear, but the helmet is quite durable and has protected the dead man’s skull and thus his brain from a large portion of the impact. Wily has been tinkering with inventions and ideas that would make Mary Shelley cringe, and has already created Bass, who integrates these ideas—that is, the synthesis of man and machine. He calls Bass a “bioroid”, rather than an android (for the sake of argument, let’s say “cyborg” isn’t a word in this man’s vocabulary).
Bass is a few circuits short of a power station, though Wily attributes this shaky sanity to the state of decay in which he exhumed the base subject. None of the brain had been left, so he attempted to salvage some form of consciousness using what DNA there was. Like the decayed state of the body itself, the mind was similarly rotted away and so he had to program a rudimentary AI and insert it alongside the human mind. Bass is functional, cunning, and vicious, but sometimes displays signs of another self or personality riding just underneath the surface. Wily, in his insanity, does not fear this, and sees it as an opportunity to learn and improve.
By the time Zero is awakened, Tom Light is gone, once more a pariah, living outside the city, only able to watch as Wily’s grip tightens and nobody knows where Protoman’s younger brother has gone. Wily’s control is complete, but still, he yearns for more. He is paranoid, as well as out of his mind, treating Zero as both son and executioner. On a whim from Wily himself, suspecting his first half-robotic creation to be disloyal, Zero kills Bass and sends the insane Wily into a rage, shrieking about someone named Emily—about someone named Tom Light. The name brings strange memories to Zero, half broken things with little framework or context. He thinks he knows this Tom Light, but doesn’t know how and fears his father’s wrath if he asks.
The curiosity is building and the dreams (nightmares, really) have grown more intense. He remembers exhilaration, determination, fire, ever-so-brief agony, and then darkness. Out patrolling the borders of the city with his heavy plasma saber at the ready, Zero chooses to take matters into his own hands, finally, and leaves entirely, searching for this Tom Light. Maybe he has the answers his father, Albert Wily, cannot, or will not provide.