Villain of my own novel - Chapter 38 37. The Obituary Colosseum.

I have experienced all the eight sufferings of this world.

I do not ask for nirvana, but for you.

Wild and hard-to-tame demon (gong) x cold, ascetic and childish immortal (shou)

- Description from Novelupdates

Protagonist travels between different anime worlds to right wrongs and uncover his reason for being along the way.

To sum up in a sentence, *slag men **washing white daily, transmigrating to different worlds to wash white, and the goal is to become a good man!

Note:
*Slag men refer to men who play with women’s hearts aka scum.
**Washing white means to come clean, fix up your life.

- Description from Novelupdates

In the foreign world, the martial artists dominate the world and the sword of the emperor controls the fate of hundreds of millions of lives! Long Yu, the number one killer on Earth, after dying, takes rebirth in this new world in an aristocratic family of martial artists but faces rejection because he is unable to practice martial arts.