Battles takes place on that island where Superman fought Doomsday.
Garp's allowed to fully heal between battles, got acces to any Marine equipment(like his trademark ridiculously giant cannonball), has intel on his opponents gathered by CP-9 who infiltrated earth beforehand.
1. Wonder Woman
3. Martian Manhunter
6. Darkseid (no Omega Beam instakill)
8.5. "World of cardboard" Superman
9. Prime Garp (magnify power by a factor of x3-x4) vs Golden Amazo (no shenanigans, pure brutal strength)
10. Current Garp vs Golden Amazo (same as above).
Monkey D. Garp:
While "only" a vice-admiral in rank, Garp is one of the greatest Marine heroes, famed for being equal in power with late Pirate King, Gol D. Roger , he is considered to be on fleet-admiral's level of strength. While age took it's toll , Garp is still insanely strong, possibly the physically strongest character in OPverse, here's a calculation on his famous mega-cannonball throwing feat, http://www.narutoforums.com/showpost.php?p=38294864&postcount=121 , and he could throw it further, since he was aiming for that ship, in short, he is a several megatons + lifter. But brute strength alone isn't all that Garp's got. He is a master of Soru (local flashstep, he taught it to Coby, so it's quite logical that he should be able to use it as well), so around hypersonic speed, he also intercepted Marco, who was capable of exchanging blows with Kizaru as nearly equals, and Kizaru is prove hypersonic +, Observation Haki (combat precognition), Armament Haki (ironskin like ability that also allows to negate people's special abilities, like intangibility or rubber body). His biggest liability is his cloudcoockoolandish attitude, shared with his grandson Luffy,, he oftenly falls asleep during innapropriate situations, like when he felt asleep on duty, got slashed in the chest by a prisoner that he was supposed to be escorting, and when his men panicked, that he had died, he woken up alarmed by their screams and demanded to know who was hurt, poor sob didn't even notice a bigass wound on his chest before his men pointed it out to him, another time, he decided to enter a room via the wall (breaking it in the process), because he considered it to be more dramatic, and shortly afterward, revealed a highly secret information in casual talk, and upon realising it, asked everyone around to just forget it. So, can the Marine Hero, Garp the Fist take it or will he end up as seaking bait?