Who's the strongest Marvel superhero?
Superhero Sentry would get my vote in this category. He is superman on steroids powered by one billion suns. He can regenerate from as small as an atom. There is also:
- Nigh Invincibility: The Sentry is, for all intents and purposes, almost completely impervious to harm, unless he wills himself to be killed he has shown no direct weakness. He has been seen surviving extremely harsh atmospheric conditions, including the vacuums of space. Nick Fury has stated that so far S.H.I.E.L.D. has yet to find a way to kill him, and even Iron Man's scanners found no physiological weaknesses in the Sentry's body. Like all of his abilities, his durability depends on his mental state, he can go to completely no-selling Class 100-level characters but as soon as he wishes himself dead he could be killed in an instant, notably in Siege where he asked Thor to kill him. He has also been damaged when he requested to Hulk to punch him in during the Green Goliath's takeover of Manhattan to prevent himself from destroying everyone on the Earth.
If nothing else that makes him the most powerful hero.