To prove me wrong, you have to either prove hedonism and hedonistic utilitarianism wrong first, or prove that a being with unlimited power wouldn't understand that it would be best for him to fill the universe with as much happiness as possible and experience all that happiness.

I'm not sure about 'proof' but hedonistic utilitarianism can be casually dismissed out of hand as not particularly desirable and the idea that giving a being ultimate power will make them adopt such preferences is absurd.