Warning! Contains Spoilers For Superman #21!
Due to the never ending nature of comic books, it’s completely reasonable thatSupermanwould wish that some of his villains would just go away forever. Some villains like Toy Maker can be truly defeated by reforming them. Other villains like Brainiac can even be reasoned with depending on the interpretation. Still,Doomsdayhas always been unrelenting, leaving Superman to wish he could defeat him forever. Now, it seems the superhero has forgotten he already took the threat down.
Superman has been fighting Doomsday for decades, and he’s been a consistent threat to the Super-Family. Young Jon Kent even used to consider Doomsday the family boogeyman. It seems like no matter whatSuperman does, he can never beat Doomsday.Doomsday has been killed and sent to Hell, and Doomsday simply broke out again. Superman had trapped Doomsday in an infinite teleportation loop, and he was able to escape that as well.

Superman even tried Trapping Doomsday in the Phantom Zone only for him to break out with sheer physical strength. Superman laments to Lois Lane inSuperman#21 by Joshua Williamson and Dan Mora that he wishes he knew how to defeat Doomsday once and for all so they could be free of him. The problem is this: Superman defeated Doomsday way back in 1994 and has seemingly completely forgot about it.
Superman has fought Doomsdaya lot,and he’s tried a ton of different ways to kill him. The only successful method was way back inSuperman/Doomsday: Hunter/Preywhere, after Doomsday absolutely demolishes Darkseid, Superman uses the help of Waverider to bring Doomsday to the end of the universe. After all, at the very end of time, the only thing left in existence is entropy. Faced with literal oblivion, Doomsday is simply wiped from existence. Not even Doomsday’s evolution can face the end of existence. However, it seems Superman has completely forgotten that he did this.

Doomsday Is a DC Calamity, And These 10 Superpowers Prove the Being Is a God
Superman regularly goes up against some of the most powerful villains the DC Universe has to offer, but Doomsday stands above most of them.
While it’s true Doomsday is still around today, that’s only due to some very special circumstances. When Superman brought Doomsday to the end of time, he did die. The only reason he’s still alive these days is due to Hal Jordan enacting the Zero Hour Crisis and Brainiac’s interference. Using the time disruption caused by Zero Hour, Brainiac managed to pluck Doomsday from the timeline immediately after Superman left him at the end of the universe. Presumably, if Superman simply took Doomsday there again, then he would finally be rid of the beast. If it worked once, what is to stop the plan from working again?

Superman Defeated Doomsday Over 20 Years Ago
Apparently, the Hero Forgot How He Did It
Some people might argue that this Superman is a different Superman from the one who killed Doomsday and therefore wouldn’t have knowledge of the plan. The problem with that assumption is post-New 52Superman and pre-New 52Superman were merged during the events ofSuperman: Rebornby Dan Jurgens and Peter Tomasi. The combination means this Superman should haveallthe memories of any previous Superman adventures. Even ignoring that,Infinite Frontieralsostated that everything is canon. This means that the only logical explanation is that Superman simply took one too many blows to the head and totally forgot he killedDoomsdayalready.
Superman#21is on sale now from DC Comics!
Superman
The icon who launched the entire world of superheroes, the last son of Krypton escaped his dying world to crash land on Earth and be raised as Clark Kent. The world knows him better as Superman, the Man of Steel, the leader of the Justice League, and the most well-known hero in the DC Comics Universe. Blessed with the powers of a demigod, Kal-El of Krypton fights enemies both small and cosmic in his endless pursuit of truth, justice, and a better tomorrow.
