MTL - History’s Strongest Senior Brother - ~ 1781. The variables are not exhausted!

The leader of the thousand demons, the Demon God Chun YeoWoon. Due to an unfortunate accident, he had been sent to the distant future.

“Listen, buddy, your cock was the last thing that got inside me, so unless I’m having some kind of miracle baby, yeah, you’re the father. Congrats.”—Raelynn had one goal that night—drown her sorrows in cheap whiskey after getting fired from her job. What she didn’t plan on was two surprises: one, a steamy night with a ridiculously good-looking stranger, and two, a $10,000 check for her the next morning. Jackpot, right?Wrong.Nothing could’ve prepared her for the biggest surprise of all—she’s pregnant. And the father? None other than Elion Vaelorian, the country’s richest and most powerful businessman, with a face that could melt ice... and a personality just as cold.What Raelynn doesn’t know is that Elion isn’t just any man. And the baby she’s carrying? Let’s just say it’s far from ordinary, and its existence could shake the foundations of the world she knows.

In the Kunlun Snow Palace, a sage once said, those who pass away wander, while the living cannot let go.Once the soul departs, it will wither like the autumn grass.Those who are reborn from the dead, existing apart from the mortal realm, shall be shunned by all celestial sects and smitten as undead demons.On this day, a youth awakens from within a coffin, his blood dry and his bones chilled, to find himself a century old upon opening his eyes.A single tear from a sage awaited, a constant companion, may unravel the dreams of the past.Seeking not immortality but a mundane death, not to lament with the ages over lost love and resentment, but only wishing to grow old with tenderness in this lifetime, beneath the white clouds that hold no envy for the heavenly realms.

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