One Piece: Seaside System - Chapter 5: Marine Based -

When the stars all over the sky open a door on the ground, the disorder of the solar terms becomes pollution, which is a disaster for the world.

Season division came into being.

At the flick of the fingers of the Lixia Commander, thunder and punishment fell from the sky!

Tomb-sweeping Day ordered the master to kneel in front of the grave, and my ancestors saved me!

…

- Description from novelbuddy

Tian Han was a young boy who admired immortals. His dream had always been to become like them—flying on swords, using spells. But he was just an ordinary village boy, and he didn't have much of a chance for that. So, he always read books about immortals, and his admiration for them grew more and more every day. One day, he heard that he had a chance to become an immortal.“You can become immortal.”This was the sentence where his adventure began. Yes, he could become an immortal. And so, his journey started, and he found himself in the ruthless world of immortals.

The so-called 『Enjoy the Human Lives Show Humans Sent to Another World With a Cheat』was trending amongst the Gods. Kanbara Kanata, one of the chosen humans ended up incurring the Evil God’s wrath and as a result, was sent to the worst dungeon,《Cocytus》. But, in a place where he was supposed to lose his life, he met Lunaère, a self-proclaimed misanthropic immortal girl. He was saved by her, who then decided to train him ’till he could at least protect himself.「Master, I think… I’ve become strong enough.」「It’s Not enough! Erm, outside of this dungeon is a dangerous place you know!」「Seriously!? More dangerous than this place…」This is the story of Kanata who was trained by his master, who easily succumbed to loneliness, till he became the greatest hero of legend, and yet was unaware of it.

The objective was the World Domination.

108 Demons and their Dungeons descended upon the land as they battled each other to become the Strongest Dungeon Master.

Isaac Constantine, a Demon Baron who managed to survive until the end of the game, only to meet betrayal that lead to his death.

Just as he thought it was over, he received a second chance

[Artefact Sand of Time has been activated.]

[Players can restart the game.]

[Synchronizing…]

[Displaying status]

[Isaac Constantine - Rank 99]

The battle between Dungeon Masters has restarted!

With a thirst for revenge, Isaac swore to create the best Dungeon and the Strongest army to win the game. Demons, Monsters, Superhumans even God himself will know his name.

Follow Isaac's story as he Rebirth to become the strongest Dungeon master