I know no-one can defeat him, but which shinobi have the closest chance? I think that Juubi, Naruto, Hashirama and a few others could defeat him. Well, what do you think? Which shinobi have the closest chance of defeating, the "God of Shinobi"?
No one, he beat the Juubi in its complete form and become its Jinchuriki. Further creating the Bijuu and the moon makes him out to be far more powerful than all the others. He's simply said a combination of Madara, Hashirama and Nagato with techniques on a far higher level, as he's the origin of all that powers.
Even though No matter what no one can defeat him. Probably Naruto and Hashi and Madara have the biggest chance out of everybody. They last 20 secs while everybody else lasts 0-10 seconds
no one. he faced complete juubi not the incomplete one and mastered rinnegan/creation of all things/chibaku tensei. only incomplete juubi would even scratch him