Dungeon Diver: Stealing A Monster's Power - Chapter 6

A woman from ancient times falls in love with her soulmate.

The end of the world is coming, the world has undergone great changes, and everything has changed. Plants, animals, and even insects, as long as there are living things, have mutated.
Become more powerful, and even evolved supernatural abilities, such as chickens and ducks that can fly to the sky, such as cats and dogs that can breathe fire.
But only humans, without any obvious changes, seem to have fallen from the top of the food chain to the bottom of the food chain overnight.
Any creature that can open its mouth to eat can treat humans as food.
But fortunately, this world has not completely killed humans. Gradually, humans discovered that they had the ability to cultivate compatibility with other creatures.
As long as it has a high degree of compatibility with some powerful mutant creatures, it can be used for its own use to achieve the purpose of protecting itself.
Fang He is a person who is very compatible with mutant animals, but it is also because of his ability that he has changed from the strongest to the stupidest.
Fang He, who was reborn, said, “Hmph, this time…”

- Description from novelbuddy

Steven awakens to a nightmare. Transported to a brutal medieval kingdom on a faraway world, he wakes up as Kivamus, the exiled third son of a Duke. Now he’s the newly made Baron of a crumbling village called Tiranat, in a bandit-ridden frontier located within untamed forests. Here, survival is a daily battle, resources are scarce, and technology is a distant dream. Yet, he sees potential where the villagers only see struggle. He dreams of using his knowledge to forge a new future for Tiranat, a future fueled by industry. But the path to progress is not going to be easy. Managing a starving village in the coming winter and navigating the cut-throat world of medieval nobility is just the beginning. This is a slow-progression kingdom-builder story, with a lot of focus on worldbuilding and eventually, industrialization and tech-uplifting. The story is going to be very, very long. Settle in for a slow-burn slice of life, where the journey is just as important as the destination. Welcome aboard!

In regards to the MMORPG Cross Reverie, Sakamoto Takuma boasted an overwhelming strength that was enough for him to be called the Demon King by the other players. One day, he gets summoned to another world with his appearance in the game. There, there are two people that insist “I am the real summon master.” Takuma gets slave-turning magic used for summoned beasts cast on him by the girls –