Mythical Era: My Electric Eel Clone Can Evolve Infinitely - Chapter 68 - : Thunder Breath, Lightning Strike

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

Each stroke of good luck is a triumph over someone else’s misfortune.Jack Grim, the son of two legendary assassins, was born and raised on nothing but coldness, and the skills to spill blood.At seventeen, Jack received his final task as an assassin apprentice under his parents.“Succeed, and you’ll run your own organization — live the life you’ve always dreamed of.”For Jack, it was everything he had ever wanted: the chance to finally become the professional assassin he was born to be.He struck his target at midnight, succeeded, and received everything his parents had promised.But in the wake of victory came a pounding headache, a relentless fever—and then… transmigration.Jack now found himself in Raiden’s body, the keeper of the Book of Ashes, the heart of the Devourer, and the very book the coward Raiden had died protecting with his life.Jack had no desire to live in another world, magic or not. He simply wanted to return to his life as an assassin.But duty had other plans. The balance of this world now rested on his ability to protect the book, and like it or not, the responsibility was his to bear.