Gekitotsu no Hexennacht - Volume 1, Chapter 14: There Lies Justice

When Li Xianyu was 20 years old, he received his father’s inheritance, an 18-year-old great-grandmother who was incredibly beautiful.

Li Xianyu: “Great-Grandma, why are you so young?”

Great-Grandma: “That’s because I died when I was 18 years old.”

- Description from Novelupdates

Year 20XX, the world was thrown into chaos when the Tower of Yxthar appeared...A colossal structure reaching beyond the sky, its countless floors each a gateway to a different world. These realms, seemingly connected to distant universes, spilled their dangers into Earth, unleashing monsters, invaders, and unknown horrors that threatened humanity’s survival.But from this catastrophe emerged an era of superhumans.... individuals awakened with extraordinary abilities.They became known as Stream Hunters, a title with dual meaning:“Hunter” for their combat prowess and “Streamer” because they broadcast their battles not just to Earth but across the multiverse.Through their streams, Stream Hunters gained viewers from other worlds, earning gifts and, if fortunate, the backing of a powerful Main Sponsor.Adam, an average ranking Stream Hunter, was just a background figure in their adventures... until the unimaginable happened.He woke up fifteen years before the catastrophe that would doom the world!Resigned to enjoying what little time he had left, Adam prepared for an arduous journey...But fate had another twist: he unlocked the Multiversal Livestream System...Granting him the power to copy the skills of his viewers.

Reincarnated into the Douluo Continent, inheriting the Emerald Scorpion Martial Soul, with no other options—what should you do if you’re forced to play with poison? Chen Ming declares: “If I’m going to play with poison, I’ll make sure to excel at it. As a transmigrator, even playing with poison, I’ll set an example worth following.”(Anti-Tang San, multiple female leads, no affiliation with the Spirit Hall, self-created divine position.)Raw Title: 斗罗：翡翠毒皇

The world was once at war with 10 alternate worlds. This was known as the Concept War and our world won 60 years ago. All of this was concealed so no normal people are aware of this fact in the current time.

After the death of his grandfather, the high-school student Sayama Mikoto is suddenly summoned by the giant corporation IAI. He learns this world is headed for destruction due to the acceleration of the Minus Concepts. To prevent this, negotiations must be undertaken with the survivors of the other parallel worlds so their 10 concepts can be released.

And so Sayama is caught up in the final battle to clean up after the Concept War which left behind so much enmity.