Superman and The Silver Surfer switch
Superman must live and protect the Marvel Universe for the next 10 years without getting killed in order to get back to his own universe....
Silver Surfer must live and Protect Dc Earth for the next 10 years without getting killed in order to get back to his own universe......
How do they do? Pretty much, Supes has to hold SS"s place down till he can gets back and SS has to do the same for Supes till he can get back........What happens? Can they do it?
Superman is not tied to Galactus..... He just must help protect the Marvel Universe as best as he can when duty calls...Supes will spend more tme in space like Surfer does when he was in the Marvel Universe and Surfer will spend more time on DC Earth like Superman did when he lived in the DC Universe...
Superman has his own current powers.....He and Surfer or even Galactus are not tied to eachother at all, just that supes helps to protect the Marvel universe as he roams the universe much like SS did......