Nanomancer Rising: Divine Alchemist Reborn as Academy's Worst Teacher - Chapter 15: Tesh’s Nightly Escapade (2)

A supreme expert in the Immortal World had died, and a strand of his soul returned to its original body on Earth. Tang Xiu discovered with amazement that ten thousand years passed in the Immortal World, yet only a single year passed on Earth.

Ruthlessly betrayed by his lover and trusted friends, Tang Xiu found that his soul went back to his previous body on Earth, and, despite he spent 10,000 years in the Immortal World, just a year has passed on Earth and many things have changed. Having an unsurpassed knowledge, Tang Xiu will protect his loved ones and go back to the Immortal World to take his revenge.

- Description from Novelupdates

A normal guy gets hit by a truck and isekai'd. Why? Because trucks are apparently some cosmic loophole. He decides to be a dungeon, because it sounds weird and interesting to be one. Is it? Let's find out.

Due to an unexpected turn of events, Xia Fei consumed a Super Gene Optimization Fluid that bore no brand, expiry date, instructions or stated its place of origin.
Our story begins here…

Mason was a mercenary, until the day he died on a mission after being betrayed by his unit.