Thanos, also known as the Mad Titan, is one of the most formidable villains in the Marvel Universe. He possesses superhuman strength, durability, and agility, as well as genius-level intellect. His obsession with the Infinity Stones makes him a cosmic threat capable of reshaping reality itself.

Galactus is a cosmic entity known as the Devourer of Worlds. He has immeasurable power and feeds on the energy of planets to sustain himself. Galactus is virtually unstoppable and is one of the most significant cosmic threats in the Marvel Universe.

Dormammu is a powerful mystical entity and a frequent adversary of Doctor Strange. He rules over the Dark Dimension and wields vast magical abilities, making him a formidable threat to Earth and the entire multiverse.

En Sabah Nur, also known as Apocalypse, is an ancient mutant with a wide range of superhuman abilities. He possesses near-immortality, superhuman strength, telepathy, telekinesis, and the ability to enhance other mutants' powers. Apocalypse seeks to reshape the world in his image and has posed a significant threat to the X-Men and the world.

Doctor Doom is one of Marvel's most iconic villains. He is a genius scientist and sorcerer who rules the fictional nation of Latveria. Doom's technological prowess and mastery of magic make him a formidable adversary for heroes like the Fantastic Four and the Avengers.