Yeah, I know it's a video game character. I didn't really have comics as a kid, but did watch the X-men cartoon as a kid, so if you don't count megaman, I guess night crawler is my next favorite.

Mega Man X, also known as Megaman X and commonly known as "X", was created by Dr. Thomas Light an unknown number of years after the Mega Man series. X was a new type of robot with the ability to make his own decisions. Recognizing the potential danger of this model, Light sealed X away in a diagnostic capsule for over 30 years of testing. Though what happened to him during these years is not specifically mentioned, it is assumed that Dr. Light died and left his diagnostic experiments unfinished. X's capsule was uncovered by an archaeologist named Dr. Cain almost 100 years after X's creation. Excited by the possibilities X presented, Cain disregarded the warnings Light had logged in the capsule and created a legion of new robots that replicated X's free will; these robots were called "Reploids".
However, a virus that caused Reploids to turn against humans began to spread. These Reploids were dubbed "Mavericks" , and a force called the Maverick Hunters was formed to combat them. The Maverick Hunters were led by Sigma until he, too, became a Maverick and declared war against the humans. X took it upon himself to join the Maverick Hunters under leader Zero, another powerful robot (created by the evil Dr. Wily), on a mission to save Earth from Sigma.
If you aren't familiar with his powers, he basically has a gun arm that an be charged up to shoot huge energy blasts and can also take powers from the Mavericks he defeats.