Any Superman fan who hasn't picked up ACTION COMICS #900 is really doing themselves a disservice. Besides all of the many, many anniversary features that pack the 96-page issue, you're skipping out on a pretty earth-shaking twist in the ongoing Reign of Doomsday storyline. Those of you who've read it will know what I mean. To those of you who haven't, beware: spoilers after the jump.... If one Doomsday wasn't bad enough, imagine how much damage four can do? The Reign of Doomsdays continues in next month's ACTION COMICS #901...