In the Marvel Universe, few villains are more frightening and deadly as Doctor Doom. However, during the Secret Wars event from Marvel Comics, the universe's ultimate villain was decided, as the ruler of Latveria ripped the Mad Titan's skeleton from his body. Since the fight, Doom has continued to prove he's Marvel's ultimate villain while having an even higher kill count than Thanos.
Doctor Doom is one of the earliest villains to appear in the pages of Marvel Comics, as the metal mask-wearing bad guy first appeared in Fantastic Four #5 by Jack Kirby and Stan Lee back in 1962. Doom, a genius who's mastered the dark arts, has shown that he isn't afraid to kill to accomplish his goals, mainly taking down the Fantastic Four and anyone who threatens his rule on Latveria. Meanwhile, Thanos has a more self-centered approach to killing, snapping half the universe from existence with the Infinity Gauntlet in an attempt to gain the hand of the living embodiment of Death. But, when the two villains met in Secret Wars, Doom proved why he should be considered Marvel's ultimate villain over Thanos.
In Secret Wars #8 by Jonathan Hickman, Esad Ribic, Ive Svorcina, Chris Eliopoulos, and Idette Winecoor, the Multiverse was destroyed as Victor Von Doom rules Batttleworld with the incredible powers of the Beyonder. The surviving heroes from the different Multiverses try to take down Doctor Doom, while Thanos and the Annihilation Horde plan their own attack. Surprisingly, Doom offers Thanos the chance to escape with his army intact if he doesn't interfere, but the Mad Titan takes exception to being talked down to. After Thanos calls him a "weak god" and a "pretender" that should bow down to him, Doom uses his powers to rip Thanos' skeleton from his body.
Doom proved to be Marvel's ultimate villain at the height of his powers; nobody was more lethal. His title would be further solidified in a later story, as Doctor Doom destroyed an entire universe (killing more than Thanos ever has) simply because he didn't want to forgive Reed Richards. Whether it's a one-on-one battle (with Doom carrying the Beyonder's powers in Secret Wars) or measuring kill counts, Doom proved to be superior to Thanos as the universe's biggest danger. Doom never wavers, nor does he care about cosmic balance - he just wants to rule.
Thanos is definitely one of Marvel's premier villains and should be considered as such, but Doctor Doom is the ultimate villain in the universe due to his unrivaled killing numbers and the epic defeat of the Mad Titan during Secret Wars. Thanos remains one of the most badass moments in Marvel Comics history, as it showed how terrifying the latter can be when needed.
