The Calamity of Ten Thousand Heavens

Able to transmigrate freely between Earth and another world, he calmly takes on the role of a mastermind behind the scenes.

As ships transformed by supernatural powers roam the galaxy and the Fourth Calamity sweeps across billions of worlds and timelines, the true driving force remains hidden, watching the tides of change with a smile.

The greatest sound is silent, the greatest form formless. He schemes across the Myriad Worlds without a trace, ruling the fate of all races from within the Dark Sea!

P.S. In the real world, the protagonist is the only immortal.