He is a drug addict who, when searching anything to put into his vein, used a super serum.
He has Thor level power but he is a complete nut.The dude trusted Osborn during the Dark Reign because "We are both fucking psycho".
He is a Bendis pet character, we got him EVERYWHERE with his fucking dead eyes, unwillingness to do anything, because he is still, a drug addict.
See Superboy Prime whinny dialog, Sentry is at this level, with the "clever" fanboy 4th wall stuff.
When he died, it is revelead he fucked Rogue, and she loved him. That was out of nowhere. And the least indignity Sentry did.
Hickman brought it back, but he is dead again.