MTL - Seal Cultivation for Self-Improvement - Chapter 2 Hard start

“Dear, it's time for your medicine!”The beautiful and pure Holy Daughter brought over the medicine for treating his wounds.On this day, he saw betrayal with his own eyes and experienced despair with his soul...From this day forth, the Hero was dead, send paper offerings if you must!

A boy from 21st century Earth, met an accident and later was reborn in Naruto’s Ninja World.
He is born in Uchiha Family and becomes the useless brother of Itachi Uchiha and Sasuke Uchiha…. Let’s see how he changed the Naruto world.

- Description from Novelupdates

Lassen, a young man who has failed at everything in his life, has had enough. Disillusioned with the world, he decides to end it all. But instead of dying, he wakes up in a parallel world, armed with a strange system that can accomplish anything he desires. Trapped in his room, reading novels and savoring every page, he has no intention of participating in the fast-paced world outside.Yet, despite his desire for peace, the world changes every time he makes an appearance. Everyone treats him like a genius, a being capable of disrupting the very fabric of reality, without lifting a finger. A powerful system, a new life, and a world that adapts to him: why complicate things when you can have everything without effort?The Genius System tells the story of a man who, although having everything to change the world, prefers to watch it evolve from the comfort of his room, through the pages of his books.

Diablo Volfir, a mighty magician, was sealed for aeons due to the schemes of the 12 Gods, but 66666 years have passed since then, and he descends to earth once again!