Minato would jokingly beat guy, he'd push guy to the 8th gate just for laughs and see what he does, he still won't hit him he'll just teleport and keep mocking him
Hm I would just say Minato but there's no telling what Guy can do in the 8th gate. He probably could become so fast that he would be able to avoid a surprise attack from Minato after using FTG & counter attack.