I Am in Marvel with Unlimited Cards - Chapter 148: IMUC- - 147 CONFESSION

When an era came to an end, various forces set foot in cultivation to compete for immortality. A young boy who spent most of the time sleeping got lucky in the troubled times and became an unparalleled immortal who could cover the sky with a snap of fingers. Was he going to live forever?

- Description from Novelupdates

This is a story that follows the courtship between a stone from Hell and a god from Heaven that begins in the underworld and spans for three lifetimes in the mortal realm.

On his usual way to home Mikado Tsuchio fell into a hole that suddenly opened on the ground. Just like that, Tsuchio falls in a different world, he lands on a Grappler Wyvern and manages to tame it.

Tsuchio decides just like that to live in the other world, the reason for his quick decision: he wants to make a monster girl harem.