Superheroes Comic books, strips, etc Science fiction comic books, strips, etc Avengers (Fictitious characters) Good and evil Human-alien encounters Imaginary wars and battles X-Men (Fictitious characters) Antiheroes Cyborgs Extraterrestrial beings Hulk Inhumans (Fictitious characters) Mythology, Norse Supervillains Symbiosis Time travel X-Force (Fictitious characters) Young adult fiction, American