Jack of Hearts first appeared in The Deadly Hands of Kung Fu #22 (1976).
Born to a scientist father and an extraterrestrial mother, Jack Hart unknowingly developed energy abilities that threatened to consume him. His father, concealing the truth from him, developed a radioactive inhibitor called Zero Fluid, which he claimed was a new form of fuel. When Philip was slain by agents of the criminal Corporation, Jack was accidentally doused with Zero Fluid, which served as a catalyst to activate his energy powers under limited control. Developing armor to contain his energies and calling himself the Jack of Hearts (in honor of his father’s love for playing cards