If you're using a matured goku then superman prime would be Superman's final "form". Most op thing I've ever seen ever. Immune to red suns,lived in a burning sun for thousands of years and can create planets and new life in his palm. Superman prime is the definition of op as -blam!-. Immune to chryptonite and 100% invincible. Goku is still flesh and bone and has died more than once,superman prime is literally a god and doesn't require other people to transform. Energy blasts would do nothing to superman prime and his body is the strongest thing in the universe and even if he could be hurt,he'd only regenerate infinitely and instantaneously. Superman prime has never been hurt though and has no weaknesses or rivals. Over 600centuries to perfect his being. Like I said,op as shit. He can break the fourth dimension too and time travel,just punch goku as a baby. Win win. Comparing anything to superman prime though is ridiculous,he was created to have no flaws or weakness and be the strongest character to ever exist in comics and media alike. Galactus?onslaught?goku?silver surfer?jean\phoenix, etcetc all nothing in comparison. He can travel faster than light too,much faster than flash from flashpoint and gokus instant transmission ever could. Not even world war hulk can compare to superman prime. Superman prime could just destroy his mind since he has psychic abilities. Even basic superman could use heat vision to cut out parts of the brain without touching the outer skin,he did this to Manchester black. Focused his heat vision to work like a scalpel and burned away part of his brain.