Despite having the dumbest name in the history of superhero comics, the Anti-Monitor was worth fearing. A being linked with everything in his antimatter universe, he intended to be ruler over all who lived-- by killing anyone outside his own universe. His power destroyed positive-matter universes on a grand scale with no seeming effort, to the point where only five survived. Exactly how you get from "infinite" down to "five" is just one of the things Crisis on Infinite Earths is not interested in explaining to you, but it does say he destroyed thousands of universes and ended trillions of lives. Even though a whole lot of that was off-panel, that makes him the most mind-bogglingly scaled-up villain comic-book heroes have ever faced. Defeating him meant ending the whole concept of a DC Comics "multiverse," at least for a very long time. He appears in a Green Lantern story every now and again, usually with motives and power levels that don't make a lot of sense when compared to his original deal. Once you've destroyed the multiverse, there's nowhere to go but down. Who'd we miss? Did we mistakenly include anyone? Let us know in the comments!
T Campbell has written quite a few online comics series and selected work for Marvel, Archie and Tokyopop. His longest-running works are Fans, Penny and Aggie-- and his current project with co-writer Phil Kahn, Guilded Age.