After the battle with Naruto, all of Sora's demon chakra was expelled from his body, effectively taking away his ability to transform. Without a host, the unstable demon-clone dispersed into nothing. Sora using his Tailed Beast Ball.

Does Naruto defeat Sora?

Naruto hit Sora with his Shukaku-infused Rasenshuriken, effectively damaging and sealing Sora away.

Which episode does Naruto and Sora fight?

"Chikara" Episode Final.