Warning! Spoilers for Superman #21!Doomsday is the enemy of all life, which has often put him in direct conflict with Superman. The two characters have fought one another for decades, with Superman desperately trying to stop Doomsday’s attack on all living things. While it seems like Superman is the only one who ever stands up against Doomsday, DC has revealed that Doomsday has made plenty of enemies, and they’ve crossed the cosmos to get their revenge.

https://screenrant.com/doomsday-enemy-superman-cosmic-army-dc-comics/