Or...have Naruto and Sasuke eventually seal Kaguya; afterwards, her illegitimate (and distinguishably creepy) son-black Zetsu-will take over Sasuke's body. Obviously only Naruto can handle him, the battle between them dwarfs the legendary showdown between Madara and Hashirama. However, the both die - as Naruto predicted many moons ago (the creepy son dies too). Everyone realizes the folly of their ways, understands that the ninja system is broken, and decide that peace can be achieved in a community without borders. Naruto and Sasuke are honored and revered for their bravery and sacrifice in saving the world. Both are made Hokages posthumously. Eh, just a thought.