Generally speaking, you expect people to be more litigenous than they are. You'd make a great American citizen!

The Champions were a Marvel 1970s super group that pre-dated the game (the first issues were in 1975) and the game's comic didn't come out until 1986. But since one of the owners of Hero is a lawyer, they may have successfully blocked a new Marvel Champions comic. See

http://en.wikipedia.org/wiki/Champions_(comics)

While I loath Wikipedia for anything important, roving bands of angry nerds do seem to keep the comic pages pretty clean.