Naruto: A Spirit-Demon Assassin from the Foundation

After transmigrating into an orphan in Konoha's "Root," he is branded with the Cursed Tongue Eradication Seal and left on the brink of death. The protagonist, Kawamoto Kei, discovers that his soul has fused with the origin of a great spirit. When he transforms into a black cat, he can not only perfectly conceal his presence from the Cursed Seal, but also travel freely to any corner of Konoha. He patiently lies low. On the surface, he is Danzo's most obedient and cold-blooded tool, but in secret, he takes the form of a black cat, using his "Metal Manipulation" ability to control steel needles as fine as hairs. Combined with the teleportation of his "Spatial Domain," he becomes the most terrifying shadowless assassin in the Shinobi World. While building up his hidden trump cards, he gets to know Tenten, Konoha's wealthy weapons expert. Her vast collection of metal ninja tools, combined with his Metal Manipulation, creates a terrifyingly effective killing duo. He gathers evidence of Danzo's crimes, assassinates Root's senior members, and devours the resources of its laboratories. When Danzo tries to reap the rewards and stage a coup on the night of the Uchiha Clan Massacre, Kawamoto Kei finally bares his fangs, using the assassination force Danzo is most proud of to uproot Root and the entire Konoha High Command!