Scenario one: guy fights all of them separately and the eight gate is restricted and he is healthy for every match
So it's guy vs tsunade
Guy vs raikage
Guy vs onoki
Guy vs mei
Guy vs garra
Scenario two: guy vs all the 5 kages at once, he can use the eight gate
So it's guy vs tsunade
Guy vs raikage
Guy vs onoki
Guy vs mei
Guy vs garra
Scenario two: guy vs all the 5 kages at once, he can use the eight gate