Custom Made Demon King - Chapter 9: Modification Plan

Huang Dan’s pain nerve is innately different from the ordinary people. A little tore in his skin can cause him to sweat all over his body painfully to the point of him unable to make a word out.

Somehow, he began to cross world, following Mr. System to do the tasks…

In the first world, Huang Dan realizes what it means to die painfully and to live to die again.

TL’s summary:
MC suddenly transmigrated and is bind to a system, requiring him to solve mysteries. Born with a higher degree of pain sensitivity, he met different people in the different worlds and learns what kind of emotion smiling is.

- Description from Novelupdates

A mysterious natural phenomenon caused the Earth to be plunged into darkness. The world turned into an endless bloody chaos and mankind is on the brink of extinction…

Qin Tian accidentally transmigrated into a sickly body, a body with broken Dantian that was unable to practice Qigong, in another world. Fortunately, God had mercy on him by giving him a level up system. Useless? That was him in the past. Not worrying about practicing Qigong, he was now able to kill Monsters to level up. Easy! Level up when killing Monsters; level up when killing people. An unbeatable sovereign of the clan in the eyes of other people, but in his eyes, he is a glittering big BOSS.

Bound together by an imperial arranged marriage, Li Yuyan is scorned for her association with the ill and blind crown prince. Publicly, she stands up for the seemingly gentle and perfect prince, and he in turn protects her from criticism. Privately, she contemplates inheriting a fortune if he dies, while he considers eliminating her if she steps out of line. Unknown to all, the beauty and brilliance they keep hidden will unveil. During their wedding night, as she cures his blindness and cold ailment, but not his secret illness, she discovers the deceit. Realizing she's been tricked, she tries to flee, only to find herself trapped by him as he expresses his fascination with her.