What If Naruto Trained With Every Hokage For 1,000 Years?

At the Valley of the End, Sasuke's Chidori goes through Naruto's chest, and the lightning runs down into the seal on his stomach. The Eight Trigrams Seal was written with the Reaper Death Seal, and the price of that seal is kept in one place: the stomach of the Reaper. Naruto's soul falls straight through it, into the dark where every dead Hokage is locked in an eternal struggle. Hashirama. Tobirama. Hiruzen, still holding Orochimaru's arms. And Minato, holding half of Kurama. Outside, Naruto's body lies in the rain for one hour while the Nine-Tails heals the hole in his chest. Inside, his heart beats once every hundred days. That makes a thousand years. Every Hokage takes a century. Hashirama teaches him to read a face before he throws a punch. Tobirama teaches him that a shadow clone is an eye that walks. Hiruzen teaches him every nature with one hand, then tells the founders what really happened to the Uchiha. And Minato keeps quiet for three hundred years before he tells his son who he is. Then the door starts to close, Sasuke is only an hour down the road, and Kabuto is carrying him toward the border. No god mode. Naruto's body comes back twelve years old. Everything else in him is a thousand years older.