Naruto: The Outsider's Resolve - Chapter 8.13 (27)

An ordinary person who has passed through the Marvel World to gain the phagocyte ability and began to devour superpowers, and became the king of Marvel!

There are many female lords. The protagonist has gradually become the king of the Marvel world from ordinary people. The initial ability is the physique that changes through traversing. It can devour and stabilises without any side effects. The system is only an aid, you can also cross the plane!

- Description from Novelupdates

This story is centered around the man named Yi Ji-Hyuk, who has spent 1000 years in a Medieval Western fantasy-like world before returning back to the modern-day Earth. When he returns, he finds that his home is facing monster threats, and that humans with superpowers have appeared to protect the innocent people of Earth.

This novel is also known as I Possessed a Demon Sovereign

Chen Luoyang felt that something was wrong with his transmigration. After transmigrating, he possessed the body of the highest expert in the world, the Master of the Demon Cult, addressed respectfully as the Demon Sovereign.

Generally, aren’t supreme experts the ones that leave behind a wisp of their soul behind and occupy a new body of some miserable low-level youngster then they go on a journey of revenge and make a comeback?!

Or perhaps it would be transmigrating into a miserable youngster’s body and obtaining a cheat slowly walking the road to becoming a God?

But why did his transmigration seem wrong?

Now my environment is full of big shots and I feel like I’m going to be exposed!

- Description from Novelupdates