I know that "Watchmen" didn't take place within the same reality as the rest of the DC universe, but if it did, what do you think would happen in a fight between Superman and Dr. Manhattan? Who would win? Would it be a stalemate? Would Superman's invulnerability make him immune to what happened to Rorschach? Manhattan can deconstruct matter, and no matter how powerful he is Supes is comprised of matter. Supes can punch a hole through virtually anything, but Manhattan can turn intangible so that things go right through him. Manhattan can make himself 100 feet tall and can duplicate himself an undefined number of times. There is only one of Supes and he is always the same size. Manhattan doesn't need to breathe air and is immune to cold, as he can travel in space and stand naked in Antarctica uneffected. Would he also be immune to heat and be uneffected by Supes' heat vision? There's no info on Manhattan having super speed but he can teleport millions of miles in seconds, which has the same effect. I'm having trouble imagining how Superman could possibly beat Dr. Manhattan.