Minato med diffs Pain.
The soul ripping pain is a non factor.
The robot pain is a non factor.
The Naraka path is easily destroyed by flash speed and Rasengan. ^^ Same applies to non factors.
The Preta path is slice and diced by flash speed.
The animal path will actually put up the best fight here, but what can the summonings do when they can't hit Minato? Chameleon isn't invisible sniping anyone, Minato can sense! Minato also has the frogs which can hold the summonings at bay, even if they're outclassed.
Deva's 5 second interval is overrided by Minato's speed obviously. CT snipe is a flawed argument, he'll be dead from a Rasengan before he tries to attempt his "last resort" move.
Pain's only chance is CT. CT is countered by teleporting the orb elsewhere. Manga has stated Minato as a genius just like Itachi, he's going to pick up CT's weakness obviously. Anyway this fight is over before CT is even launched as stated above. But may as well counter before the CT snipers post.