Naruto: The Hidden Protector - Chapter 116: Eternal Mangekyo Sharingan

On the Great Land of China, forces clashed for the sake of supremacy and Bloodline Warriors ran amok; the conflict of the strong threatened to shatter heaven and earth. A young man named Lu Li—nothing more than a humble Coffin Carrier from the Northern Desert—came along with Lu Ling, his sister. The two were regarded as puny insects and bullied, but little did people know that Lu Li had the strongest Bloodline of them all in him.

He mounted the most handsome of horses and drank the strongest of wines;

He bedded the most beautiful of ladies and murdered the most hated of people;

He told a huge lie and carried with him an ill-reputation undeserved;

He traveled all by his lonesome and danced with devils;

He had given his word that he would come back, that he would be strong.

And it was because of this that she was still waiting in the city—alone.

- Description from Novelupdates

Fade was a legendary assassin that could kill just about anyone, as long as the price was right and the reason was just.

One day as he was reminiscing about his life when he lost someone important, he fell asleep. When he woke up he was in a weird place, a different body, a different world.

The story starts on earth, after some unknown circumstances, the world was suddenly invaded by monsters from other worlds. Many died and even more turned into zombies, starting what many would call 'The apocalypse Era'.

Rin, a normal teenage boy who lost all of his family members was on the verge of falling into despair when a goddess appeared and sent him to another world that was very similar to a game Rin played before the apocalypse.

Her goal from this was simple, trample on all the protagonists and become the strongest creature in that world for a chance to get back what he thought he lost forever.

Accompanied by a cold beauty, both of them embark on a new journey to become stronger, get back to their world and fix everything.