"Onoki easily", or "Tsunade with some difficulty". Onoki is just too hax and powerful for these Kages, guy is a ****ing beast. The only one who can survive Onoki's Jintons and flight would be Tsunade assuming she's in Byakugou/Regen mode, and she has Katsuyu which means stuff like flight shouldn't technically be a problem.
After she takes the hit I don't doubt her to be able to regenerate, problem is hitting or killing Onoki after that. I think outlasting him will be easy if he keeps trying to "kill" her with Jinton which takes quite a lot of chakra, but after all the shit that's happened in the war he's still fighting(however, it was admittedly thanks to healing by Tsunade that he's come this far).
In a fight between all 5 Kages, the answer is with absolutely no doubt Onoki, however if Tsunade is in regeneration mode assuming she gets it off before Onoki nukes the field then everyone else will die except the two. Then there's chance for Tsunade to win, it becomes an endurance battle that could go either way IMO, still leaning towards Onoki for obvious reasons.
After she takes the hit I don't doubt her to be able to regenerate, problem is hitting or killing Onoki after that. I think outlasting him will be easy if he keeps trying to "kill" her with Jinton which takes quite a lot of chakra, but after all the shit that's happened in the war he's still fighting(however, it was admittedly thanks to healing by Tsunade that he's come this far).
In a fight between all 5 Kages, the answer is with absolutely no doubt Onoki, however if Tsunade is in regeneration mode assuming she gets it off before Onoki nukes the field then everyone else will die except the two. Then there's chance for Tsunade to win, it becomes an endurance battle that could go either way IMO, still leaning towards Onoki for obvious reasons.