MTL - From the Head Pillar Tanjiro, Take Stock of the Wonderful Nicknames of Zongman - Chapter 232

[By the Author that brought you “Martial God Regressed to Level 2”]The Swordmaster, who unified the continent and vanquished the Demon King with nothing but his sword, thought he would live out his days peacefully in a world of tranquility.One day, however, he awakens 1,000 years later in the body of a distant descendant.In a world where magic is now held in higher regard than the sword, the empire has crumbled, and the imperial lineage has fallen into ruin.“More importantly, what is this pathetic excuse for a body?”He now inhabits the body of Kaylen, once known as a “walking slime”.With the demonic realm invading once again, he makes a vow:“Since I’ve mastered the sword, I might as well master magic too.”Thus begins the return of a transcendent being, armed with unparalleled magic and absolute swordsmanship, destined to save the world!

Doomsday comes, and human beings enter the heavenly world.
Ten years later, Yang Chen, who was betrayed tragically, returned strongly with the Tianyu bug. In this life, he vowed to make the betrayal pay the price. He has a powerful bug bonus, just like an open hang. Frightened to hear…

- Description from novelbuddy

The ordinary 18-year-old Edo, during a nighttime walk, finds himself in a fantasy world where he gains a mysterious power that could shape his destiny.