Naruto the Negate Challenge
Firstly this idea comes from the game Enchanted Arms. When Naruto has the kyubbi sealed inside him the kyubbi flared its chakra and according to the hyuga and medics the kyubbi's chakra destroyed the chakra path ways in naruto's right arm and while he can still channel chakra through the rest of his body his right arm was completely unstable and so to counter jiraiya placed dozens of seals along naruto's arm that flare chakra so that Naruto could perform jutsus. During naruto's second year in the academy while learning the basic three the seals failed but instead of preventing Naruto from doing jutsus he was still able to perform jutsu. He failed to notice the seals failure,years later at the mizuki scroll incident after defeating mizuki, mizuki's accomplices arrives (authors choice who) he attacks Naruto with the grand fireball jutsu, Naruto stands in front iruka as the fireball got closer it got smaller and smaller until it went out and the accomplice kept throwing jutsu at them and each time the attack either fell away before getting to Naruto and each time naruto's arm began to change, darken, and strengthen.
This challenge is Naruto with the power to negate chakra with his right arm and the more chakra he stops the more "demonic" his arm and later the rest of his body as well above is a sample of how I think the story would go in the beginning of the chapter but it is writer's desecrations