He's strong enough to beat Superman like a red-caped stepchild in at least half their brawls, and that's without his all-destroying, target-seeking Omega Beams in play. It's too far to call Thanos a knockoff of Darkseid (though many have tried): Thanos is mostly a butcher, whereas Darkseid is a tyrant and calculator, ruling the planet Apokalips and working on the Anti-Life Equation, with which he should be able to rule the universe. Yes, the entire security of the cosmos depends on this guy never mastering really advanced calculus. Nobody introduce him to Steven Hawking or we're all screwed.