Originally posted by Kid KurdyCap is also a symbol because he is a hero.Thanos isn't.Thanos does have strong willpower but i will agree with what you said about doom having higher will.
I don't know.But like I said, Thanos doubts himself. He also likes to change his opinion from time to time, sometimes being just the bad guy, other times being the good guy (more or less) or regretting his actions.
All this makes me believe he doesn't have this über willpower, that's more Dooms forte.
Captain America's willpower is so great that he has become a symbol. Thanos will never be a symbol.
Concerning his bionics and mysticism: the more powerful you are, the more self assured and strongwilled you become. So imo the upgrades Thanos gave himself made him more self assured and strongwilled.