This Naruto Doujinshi novel was called " Naruto Sword Soul ". The main character was a transmigrator. He did not have a heaven-defying cheat, but he had a mysterious sword that could cut through the sky. In this story, the protagonist turned his saber into a crow after arriving in the Country of Waves. I hope my answer can help you. If you are interested in other novels, you can tell me again.