This Ninja Is Obviously Not Strong but Really Hard to Kill - Chapter 9: Heavenly Suicide System

The scum’s or villain’s long road of transformation was tentatively set to the world:
The abandonment of the educated youth’s wife (Completed)
The hidden marriage of the scum film emperor (Completed)
The best brother in the world (Completed)
The Phoenix male who destroy the bridge after crossing the river (Completed)
The treasonous general (Completed)
I’m an honest man (Completed)
To become the top scorer in the School of Agriculture (Completed)
The soft rice man’s self-cultivation (Completed)
The whole world is reborn (Completed)
I want to survive on a desert island (Completed)
The stallion male who has seized the opportunity (Completed)
The perverted self-salvation (Completed)
The spring of the loafer (Completed)
The misplaced life (Completed)
The miser career (Completed)
The ghost is out of feeling (Completed)
The Queen’s favorite husband (Completed)
The vicious girl with her godfather (Completed)
I want to be a good person (Completed)
I does not tear up the family (Completed)
The perverted common plant (Completed)
The Mary Sue’s men (Completed)
Every time I was reborn, someone wants to kill me (Completed)
The old people’s counterattack path (Completed)
The global evolution (Completed)
When I became a net red (Completed)
For you, good person (Completed)
His heart had white moonlight (Completed)

- Description from Novelupdates

Zhangsun Zijun and Yi Xichen are the protagonists of the novel “Record of Nine Thousand Vicissitudes.” One is solid and reserved; the other is free-spirited and uninhibited. As fellow disciples under the same master who grew up together, the two have a deep friendship that was strengthened by their numerous life and death adventures together.

However, in a popular yaoi fanfiction, the personalities of these two characters is completely OOC. Zhangsun Zijun turned into an insanely jealous, insatiable s*x addict madly in love with his wife Yi Xichen. Yi Xichen turned into a sweet, delicate little angel. Their daily life was full of kinky bedroom activities…

Suddenly, the Zhangsun Zijun character from the fanfiction was transported into the world of the original novel.

- Description from Novelupdates

He crossed over to a new world where humans have magical power. They are called warriors. They use their power to kill the monsters that appear out of nowhere. Dragons, Dungeons, and Magic users are pretty common in this world. If you want to live in peace, you need to have that power. You can also become a powerful clearing dungeon.

In this dangerous world, he has a system that can help him grow stronger. But he didn't want to be a high-profile warrior who attracts much powerhouse attention or become a lab rat. He wants to be Low-profile and grow strong using his system.