Jack of Hearts (Jack Hart) is a fictional character, a superhero appearing in American comic books published by Marvel Comics. The character first appeared in Deadly Hands of Kung Fu 22, and was created by writer Bill Mantlo and artist Keith Giffen. He starred in his own 4 issue mini series and has been a regular character in the Iron Man comics as well as at one point being a regular in the Avengers comic book.
Jack of Hearts, real name Jack Heart is the son of scientist Philip Hart that created "Zero Fluid" and an alien woman from the race Contraxian. As a young man Jack was doused in Zero Fluid and gained super powers but was not in total control of his powers. In an attempt to control his powers Jack of Hearts built a containment suit that resembled The Jack of Hearts playing card. The lack of control became a recurring theme with Jack of Hearts, including his stint in the Avengers where he had to spend 14 hours a day in a containment room to prevent self destruction. When his powers became uncontrollable he chose to leave earth, exploding in space without harming any innocent bystanders.