Thanos
Species: Eternal-Deviant
Enemies: Guardians of the Galaxy, The Avengers
While Thanos is a very large individual with supreme strength, stamina, speed, and more, a lot of his most notable powers have come from the infinity stones. Of course, in Marvel Comics, Thanos is known for trying to collect all the stones and wielding them in the infinity gauntlet. One thing often misunderstood about Thanos as well is that he is a deviant, which is basically like an eternal but not quite as immortal. They are overly powered beings that can take over planets if they are not stopped.
Thanos often goes to war with alien planets and kills as many beings as possible. This is because he is obsessed with the physical embodiment of death. Since Thanos cannot really die to join her, he’s even more obsessed. She is a mistress he is obsessed over, and killing others allows him to give her many souls. Thanos is nearly successful in ending half of all life for good, giving Death her ultimate gift. Doing this would also require him to use the stones that could also weaken him heavily, and enough to die himself. Yet this does not all go quite to plan.