Iron Dynasty - Chapter 182: Retreat?

Tenjou Yuuya has been a bullied boy since the past.He lives in the home of his beloved grandfather while he goes to school. As usual, he receives a harsh bullying, and he takes an extended absence from school to have some time to heal his wounds.While on this long time of absence, he takes the opportunity to clean his grandfather’s house and goes to a room he never went before, where his grandfather keep many different objects that he gathered from his travels around the world. While he was arranging the objects, he found a door not on a wall among the objects.Out of curiosity he opens this door, what he found on the other side was…

I, Zatiel, Abyssal Lord, Ruler of Death and Destruction, Nightmare of Dys, have AWOKEN!!!!!.

His life contains events that can shake the universe:
-Fighting against Tiamat, Creator of Evil Dragonkind, in the first circle of hell, while billions of demons and devils butcher each other beneath them
-Start a World War against the Heavenly Race, and transform himself into a Golden Sun while he slaughters their greatest warriors, the Archangel.
-Enter the Final Gate and fight against the Outer Gods.
-Tearing the nine levels of Baator during his battles against the Prince of Evil, Asmodeus.

With his memories as a ruler of the Abyss and a Universal Existence, Zatiel will rise again.

Kawaki, who was born in the dragon vein of a planet (Altana), first met Umibozu who was traveling in the universe, and his girlfriend, Kouka.Later, he came to Earth by accident and met the teacher who affected his life —Yoshida Shouyou.He also met a group of friends. The most conspicuous among the group of friends is a fool with silver hair and naturally curly hair, a short man with purple hair, and a little devil whose catchphrase is “Not Zura, it's Katsura!”Gintama Doujin, not transmigration.

Thousands of years ago, a small planet collided with Earth and destroyed the world. In five days, ninety percent of humans had been wiped out, leaving behind the last ten percent to earnestly struggle on death’s door.

Jinyu was one of those people who survived. Due to a special heredity trait, he could understand beast language. After the apocalyptic disasters, Jinyu had been living for a month with the few small beast brothers that he’d subdued. Previously, Jinyu had thought that he would live like that until he died. Yet, inexplicably, one day he opened his eyes to find that he was in a monstrous, lawless world that was full of vitality and life.

Jinyu’s transmigration into the future let him skip over almost one hundred thousand years. In the year 106825, beasts rule the galaxies and ‘pure’ humans are extinct. As the one and only ‘pure’ human left in the entire universe, Jinyu braves this new chaotic world to find a place for himself and thus begins to work at Beast Store number 138.

- Description from Novelupdates