After the super-soldier serum wore off, Steve Rogers was restored to his natural age. Unable to battle any longer, he retired from the role of Captain America. Rogers chose Sam Wilson, one of his closest and most trusted allies, to take up the shield in his place.
Once, Nathaniel Essex was a biologist in Victorian London. Realizing that an increasing number of human mutations signaled the beginning of a new evolution, Essex put aside morality in his pursuit of perfecting the human race.
When the Red Skull sought an heir for his criminal empire, he fathered Sinthea Schmidt. The girl was raised with constant indoctrination of her father’s twisted views. Forced to undergo physical transformation in one of the Red Skull’s machines, she was gifted with superhuman powers.
The mutant twins Wanda and Pietro Maximoff are powerful beings who have fought on both sides of the mutant divide, as founding members of the Brotherhood of Mutants, and members in the Avengers and X-Men.