Here is a list of 16 most powerful characters in the Marvel Universe.
Vulcan is the brother of Scott Summers and Ales Summers both mutants however unlike them he is an omega level mutant. He has the ability to manipulate all forms of energy at will and can absorbs them as well, even magic. He has fought on par with the likes of Black Bolt and has fought against the X-men, Inhumans and Starjammers simultaneously though he was overpowered. He was once the Emperor of the Shi’ar Empire but is later overthrown. He is believed to be dead but it is actually unknown.
Skaar is the son of The Hulk in an alternate reality. He possesses powers similar to his father, but greater. His physical strength is so high, that he cracked the armor of the Juggernaut and sent him into the outer atmosphere with one punch, which is something that was considered impossible and that even his father failed to do. He has survived blasts from the Power Cosmic, and falls from outer space. His healing factor is superior to the likes of both Hulk and Wolverine.
Odin the monarch of Asgard and the strongest of all Asgardians, even his son Thor. He can manipulate magic for a variety of effects including strength augmentation,size augmentation, various magical enchantments, fire energy blasts, and others. He also, as the monarch of Asgard, can absorb the powers of all the Asgardians into himself to greatly augment his already formidable powers. Odin is immortal and thus cannot die die by any natural means. His regular strength level is around 60 tons.
Hercules is the son of Zeus, the Sky father and King of the Greek Gods and is thus an Olymian God Prince. Hercules is considered the physically strongest character in the whole marvel universe. Literally the strongest, even over characters such as Thor, Hulk, and the Destroyer. He has pulled the entire island of Manhattan which weighed 99,000,000,000 tons, he has overpowered the likes of Thor (who can shatter planets with his blows), manhandled the Hulk (who has shattered objects twice the size of the Earth), and literally held up the incalculable weight of the heavens which would make the weight of a planet literally seem as if nothing. In addition to his legendary strength, Hercules possesses durability to such a degree that blasts from the cosmic being Nova did not harm him at all and projectiles such as bullets are completely beneath his notice. He can survive in the vacuum of space unaided, and has near limitless stamina. He is virtually immortal and does not age at all (he is over 3000 years old but looks like a healthy man in his prime). In addition, Hercules possesses the adumantite mace (an indestructible mace)and the skin of the Namean Lion (which he wears upon his back) which protects him from virtually all harm. Despite their constant rivalry and fighting, Hercules is a long time and great friend to Thor who is the Prince of the Norse Gods.
The Grandmaster is an eternal, the same race as the Runner and the Champion. He is vastly intelligent, old, and powerful. He possesses telepathy, and other psionic powers such as telekinesis to a high degree, mind alteration, mind wipe etc. He has supernatural physical characteristics as well such as being able to lift 25 tons and having faster than human movements and reflexes. Another notable power of his is the ability to completely restore the injured or ill, no matter how heavily damaged or sick they are. But he can go even beyond that and is capable of actually bringing the dead back to life. Perhaps most notable of all, is that the Grandmaster is immortal and literally can’t be killed by any means because Death itself has banished him from the land of the dead. No matter what trajectory or cunning, the Grandmaster cannot be killed. The Grandmaster also has a mania, almost a reliance of games. They amuse him emphatically and has spent much of his time playing various games over the last few thousand years.
One of the strongest in the universe. Eats entire planets, possesses vast knowledge, unlimited cosmic power, and gave beings as strong as the Silver Surfer their power and is still in an entire different power league.
The Magus’s power is comparable to that of Galactus. His main power is unlimited shape shifting. He can become virtually any substance, any size (larger than suns), any shape, and any color. He can turn into things such as starships, cannons, etc. Potentially he could make himself into a massive cannon the size of a planet and destroy anything in space. His possibilities are limitless. He also possesses extremely powerful telepathy and can learn things such as languages in an instant.
Mikaboshi is an abstract being of far greater power than even the Sky father beings such as Odin or Zeus. He has defeated Zeus, the king of the Sky father and most powerful of the Greek Gods on 2 separate occasions. His powers include immortality, shape-shifting,super strength, various energy projections, etc.
Cyttorak is possibly the single strongest magical being in all of the marvel universe. His power is so great that even Galactus, was helpless to free himself from the power of Cytorrak, who had imprisoned Galactus. He is the source of the powerful Juggernaut’s power and the elite magicians of the universe including Dr. Strange, and even Dormammu and Zom, invoke Cyttorak’s name to power their spells. Inside his own dimension, Cyttorak’s power is limitless.
7. Phoenix Force
Phoenix Force is the most feared being in the universe. Single handedly defeated Galactus himself and over powered even the mkraan crystal.
6. Franklin Richards
One of the rare omega level mutants, He has the ability to warp reality on a much more massive scale than Proteus. Though in his child form he never could completely control his immeasurable powers, however it is said that his power equals that of the Celestials. He i quite possibly the strongest mutant to ever exist.
The very embodiment of time. Eternity can manipulate space, time, and reality itself as he wishes. His power is greater even than the likes of Galactus.
4. Living Tribunal
The living tribunal is considered the second strongest being in the marvel universe second only to the one above all (and later on, The Beyonder). He is so powerful that even Thanos with the infinity gauntlet making him stronger than the entire marvel universe combined did not dare to engage The Living Tribunal in combat. The living tribunal is the supreme authority in the marvel universe save The One Above All. His power is absolutely limitless.
A near omnipotent and vastly powerful mutant inhuman. He is the most powerful being in the Marvel multiverse second alone to The One Above All. He was so strong, that all the Marvel abstracts (such as Eternity, Infinity and Death), supreme cosmic beings (such as Galactus and the Stranger), and The Living Tribunal himself were left at his mercy.
One-Above-All is the most powerful being in the marvel multiverse. He alone possesses greater power than the living tribunal and Beyonder. He is believed to represent the creators of marvel (Jack Kirby and Stan Lee) And while he is technically another entity, he has taken the form of Jack Kirby to demonstrate what he really is which is the grand authority in the marvel universe.
In the storyline Deadpool Kills the Marvel Universe, the X-Men sends Deadpool to a mental hospital for therapy. The doctor treating him is actually Psycho-Man in disguise, who attempts to torture and brainwash Deadpool into becoming his personal minion. The procedure fails, but leaves Deadpool even more mentally unhinged; as a result, he kills Psycho-Man and begins assassinating every superhero and supervillain in Marvel Universe (everyone listed above) one by one in an attempt (apparently) to rebel against his comic book creators. The book ends with him breaking into the ‘real’ world and confronting the Marvel writers and artists who are currently writing the book. Before he proceeds to enter he turns to the reader, promising that once he’s done with this universe, “I’ll find you soon enough.”