The Great Mage Returns After 4000 Years (Web Novel KR) - Vol 2 Chapter 411

Tsubasa gets a second chance, reincarnated in the Naruto world.However, fate throws him into the Sengoku era, a time of relentless conflict.His sole advantage? A one-time cheat to create a ninjutsu. 'Venom' is his creation, his hope.Can this single ninjutsu ensure his survival and perhaps, something more, in this savage age?

In the 5th year of Konoha’s founding.The battle between Hashirama Senju and Madara Uchiha at the Valley of the End had come to a close.In order to treat his elder brother’s injuries, Tobirama Senju resurrected a medical ninja from ancient times, hoping that this individual could prevent the injuries from shortening his brother’s lifespan.This medical ninja’s name was Emiya Shigen.

It begins on the mountain.

With the glint of a knife, a flash of steel in the hands of a sworn brother. A betrayal.

Stabbed and pushed down the mountain, Zi Chen lied within the red-stained snow, left to die.

This is where it begins; he is given life by lightning,
baptized by thunder.

Those who had once betrayed him should all suffer in his cruel revenge.

- Description from Novelupdates