Zero (Mega Man X)

Zero (ゼロ?) is one of the three main characters of the Mega Man X series, as well as the protagonist of the Mega Man Zero series. He also makes an appearance as Biometal Model Z in the Mega Man ZX series. A high ranking Maverick Hunter in the X series, and a legendary freedom fighter in theZero series, he's a die hard warrior who doesn't hesitate to take action. However, behind his cold and emotionless attitude lies a wounded soul.

Backstory
After Wily created Bass in Megaman 7 who betrayed him in order to prove he was the strongest. Wily studied the bassnium and created Zero along with often dubbing him as his greatest masterpiece and regulary checked on him during his development. However, Zero contained a large flaw in his cognitive brain that made him violent and disobedient, not wanting to risk severe havoc, Wily sealed Zero away in a capsule where he was later found by the gamma unit approximately 100 years after the Classic Megaman series took place. Zero awoke as a maverick and destroyed all the members, former Maverick Hunter Sigma went to battle Zero and was almost defeated by him but a glowing W symbol caused Zero immense pain and Sigma destroyed it knocking Zero unconscious. Zero later joined the Maverick Hunters but Sigma unfortunately had picked up a virus from him which made him become evil and setting up the events of the Megaman X Series.