Source: comicbook.com

9. The Sentry

Drug of Choice: Sentry Serum

Oh, The Sentry, why are you coming back? No one likes you. Ah, well,  Jeff Lemire’s going to write the new series, so it could actually be good.

But anyway. The Sentry initially seemed to be a long lost and forgotten Marvel character from the Silver Age. But the truth is that his evil archnemesis, The Void, is actually an extra personality that exists in The Sentry's head, and the truth comes out when the character finally well and truly snaps.

Bob Reynolds is a hopeless addict who breaks into labs to steal narcotic substances. One night, he breaks into someplace he absolutely shouldn't, and drinks down a serum produced in an attempt to produce vast powers by reproducing and overclocking the Super Soldier Serum.

Sentry uses his newfound powers to fight crime and then to murder hundreds. Then Thor beats him to death.