Naruto: I'm Kakashi, and I Can Go Fifty-Fifty With Anyone

A boy who loves Naruto accidentally transmigrates to the Naruto world and is reborn as Kakashi, who can go toe-to-toe with anyone. He also unlocks the Strongest Even-Match System.

As long as he fights an important character identified by the System and manages to match them evenly, he can receive a System reward.

Deva Path Pain: You say you're a god, but your style is even more outrageous than mine. You even ask how many floors a bag of rice can be carried up. I'll match you evenly.

Six Paths Obito: You say you're the most devoted man in the Shinobi World, and you want to create a world with Rin in it once more. I'll match you evenly.

Six Paths Madara: You say you're Konoha's Dancing King and the Asura of the Ninja World, and you want me to dance for your amusement. I'll match you evenly.

Kaguya: You say you're the progenitor of chakra and the mother of the Sage of Six Paths. I'll match you evenly.

Ōtsutsuki Isshiki: You say you can beat Naruto and Sasuke when you're nearly out of chakra, and that you're invincible at full strength. I'll match you evenly.

In this life, Kakashi never runs out of chakra. With the Rinnegan, the Tenseigan, and the God Tree Fruit, he leads Naruto and Sasuke in a counterattack against the Ōtsutsuki.