In Different World with Naruto System (WN) - Chapter 91 Night Raid

Above the firmament, a giant Kun, stretching thousands of meters long, flew over the city, ignoring the barrage of missiles.In Australia, an apocalyptic serpent, thousands of meters long, destroyed cities and devoured millions, leaving slowly after the detonation of several nuclear bombs.In this perilous world, Chen Chu, who unexpectedly acquired the avatar of a six-horned salamander, felt somewhat bewildered.What could a palm-sized salamander do? Record videos to gain traffic? Catch shrimps in a creek? Or... evolve into a colossal beast?A six-horned salamander, also known as the six-horned dragon, with the ability of infinite evolution, was gradually evolving into a mythical apocalyptic beast.Its body length extended to hundreds, thousands, and even tens of thousands of meters...And with the characteristic of synchronized enhancement, Chen Chu's own body also grew stronger, with increasing power and speed, and even...

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

- Description from Novelupdates

A fighting genius.

Su Yun was a prodigy, blessed by the gods. However, life is never so easy. Soon after reaching 6th stage in spirit novice realm cultivation, his progress stagnated due to incurring a rare medical condition.