American Exorcism Male God - Chapter 19 - The Final Key

At 18, Alex Kain is whisked away to Eryndor, a game-like realm where he gains 'Skill Synthesis', a talent to fuse skills into godlike powers. Battling monsters and conquering dungeons, he builds a harem of strong women drawn to his might and charm. With the power to return to Earth bearing incredible resources, Alex faces a growing threat that endangers both worlds in this epic of adventure, romance, and ambition.

A long time ago, the decayed main god space collapsed and disintegrated, and the wreckage was scattered in parallel universes, giving birth to a new space…

Countless ‘story worlds’ under control have also fallen into the void, regained freedom, runaway out of control, elevated to reality, and turned into reality.

At the same time, these “worlds” are polluted and corroded by the void, giving birth to greater fear and filth…

…

The space of birth feeds on the world.

They compete with each other, their tentacles penetrate through dimensions, invade different time and space, search for the legacy of the main god, drive the apostles to be minions, greedily tearing, seizing, devouring, and reclaiming one world after another, so that they can return to greatness.

…

The innocent eating melon and white waves with the legacy of the Lord God accidentally got involved in the parallel universe “Paradise of Fire” during a cross-border call.

After forcibly binding the demi-human blood, he became an excellent tool man who can repeatedly die, starting the legendary ‘dimension invasion career’.

- Description from novelbuddy

Darkness. The ultimate ruler, the true One-Above-All. Everything starts from it, and everything returns to it eventually. People say that in your final moments, darkness seeps in your very existence, engulfs your whole being. They say it’s an incredibly relaxing feeling that takes you on your journey to your afterlife. They say that in the very darkness, the ‘nothingness’ your weary soul will finally be able to rest and relax. This brings up some very philosophical and existential questions. Do you even exist?

Follow the epic journey of Aiden, the last primal, a unique and ancient race as he finds his place in a strange, new world, filled with threats and violence.