So.. yeah.. what villain from either Universe would do the most damage?
Thanos basically made himself the "master of all things", with the Tribunal simply stating it's the natural progression of things and looking the other way (even after Thanos overpowers Eternity/Galactus/Celestials (? I forget if he smoked the Celestials or not)), but Nebula ultimately took advantage of his arrogance and he was "defeated", and the chaos he brought forth with the IG was undone. Thanos is his own worst enemy or he'd still possess the Gauntlet, undoubtedly.
Which villain wouldn't suffer from shooting themselves in the foot, and would achieve and successfully (for a time spanning longer than a mini-series
) maintain their idea of Godhood?
What do you think they would do first?
Let's not make this characters who already are deities, like Galactus/Spectre/etc... let's make this limited to people who put their spandex leotards on one leg at a time every morning.