Sasuke kills Naruto, only for Naruto to point to his left. Sasuke kills Naruto, only for Naruto to point to his left. Sasuke kills Naruto, only for Naruto to point to his left.
As it turns out, Naruto learns that making up your own seals on the fly is NOT advised, and now Sasuke is trapped in a jury-rigged version of Izanami forcibly powered by his own Rinnegan power. Naruto still hasn't figured out if there's a way out of it, so he leaves Sasuke in Sakura's care while he wanders the land in search of a cure.