One Piece: Don't Worry, I'm a Doctor - Chapter 299: You Living the Good Life? No Way!

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

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.

- Description from Novelupdates

Jin Runcandel is the youngest son of the greatest Swordmaster. After he gets himself kicked out of their clan, he meets a tragic fate…but before he dies, a God gives him a second chance. Now he must use his new power for good.

Lin Fan was transported to another world, into the body of a normal disciple. Given the environment he was in, Lin Fan faced the risk of being killed at any time. However, something was out of place.