It's in my firm opinion, that WW Hulk who is also the World Breaker Hulk and beyond, could handle Thanos by himself, all that he would have to do is take it up. I'd go as far as to say that he can compete against Thanos even if he used all of his powers.
Thanos is a beast, but through purely physical means (aka slugfest) how does he put those two down? Both have insane regen, Colossus has the unstoppable enchantment and hulk just keeps getting stronger. Both are immortal. Both amp up the more bloodlusted they become, so the longer the fight the more it favors the two. hulks gets angrier and colossus causes more destruction equals a win for the team. These are the last two heroes you want to engage in a straight up brawl.
Thanos using all his powers wins...but in a slugfest against these two monsters, after a long long fight I see the team outlasting him.
He ate people, just look at him, he has an arm in his mouth. > Thanos
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