An Eldritch God Takes Me Across the Multiverse

Not long after Cheng Yu transmigrates into a modern urban world, an ordinary-looking man appears before him and tells him that his system is a fragment of the man's divine authority. Oh, and he says his name is Yog-as in Yog-Sothoth...

Cheng Yu: "After becoming Lord Yog's apostle, I match wits and trade blows with the usual urban-fiction protagonists in the modern world.

"In a fantasy world, I unleash the Third Cataclysm. A tidal wave of intelligent machines sweeps away everything. Flesh is weak; through machinery, we ascend.

"In a world of supernatural horrors, I bravely battle the King of Horrors. In the end, I sever the connection between heaven and earth, ridding that world of supernatural horrors forever.

"In a world where hidden masterminds pull the strings of creation, I become a god of world destruction. The Creator God and I use the sea of stars as our chessboard and civilizations as our pieces. Finally, I unleash heavenly punishment upon the stars, annihilating everything.

"In worlds of mystical cultivation, in the Sea of Chaos, in the worlds of the Cthulhu Mythos... Eventually...

"Beneath the gaze of His Majesty Yog-Sothoth, the great All-in-One, I finally become an Unspeakable One!"

(No female lead, a semi-invincible protagonist, and no harem. Not for readers looking for mindless power fantasies or dark fiction.)