Mastermind (Jason Wyngarde) is a fictional supervillain appearing in American comic books published by Marvel Comics. He most often appears as an adversary of the X-Men. The original Mastermind was a mutant with the psionic ability to generate complex telepathic illusions at will that cause his victims to see whatever he wishes them to see. He was a founding member of the first Brotherhood of Evil Mutants and later a probationary member of the Lords Cardinal of the Hellfire Club, where he played an important role in "The Dark Phoenix Saga".