Marvel vs. Capcom/Cable

Cable has an entirely interesting, yet confusing past. He was born Nathan Summers in the modern day to Scott Summers (aka Cyclops) and Madelyn Prior (who was later revealed to be a genetic clone of Jean Gray). As the son of two very powerful mutants, he is very powerful as well. However, at a young age, Apocalypse infected him with a virus called the techno-organic virus which threatened to kill him. A being from 2000 years in the future named Askani appeared, claiming that Cable was destined to save their people, and that they would cure him of the disease. Cyclops agreed to let his son go in order to save him

Cable did travel to the future, but his disease could not be cured. Instead, he was trained to use his telekinetic abilities to keep what damage the techno-organic virus had done to his body in check so it could not grow beyond control. As a teenager Cable ultimately defeated Apocalypse. As a grown up, he returned to his own time in order to deal with a clone of himself named Stryfe, who had become a madman. While he remained active in the present, he frequently engaged in time travel whenever the need arose.

As a mutant, Cable's physical attributes have been enhanced to superhuman levels. His principal mutant powers are his vast telepathic and telekinetic abilities. He can employ the latter to levitate objects and to create protective force shields. He must continually employ his telekinetic powers to prevent the techno-organic virus from affecting the rest of his body. His techno-organic left arm and shoulder possess even greater strength than his entirely organic ones. Cable's techno-organic right eye can see into the infrared portion of the spectrum. He is also a highly accomplished warrior and battle strategist, highly adept in multiple forms of hand-to-hand combat and in the uses of many kinds of weaponry, both of the 20th and 40th Centuries.

Cable could very well be the most powerful mutant in the Marvel universe, if it were not for his need to use a portion of his powers to keep the techno-organic virus in check.