MTL - What if My Brother is Too Good? - Chapter 3 Forced love

This world has Fox Fairies, River Gods, Water Monsters, Great Demons and Cultivators who seek immortality.

An innocent boy from Earth who was sheltered all his life finds himself reincarnated into a world full of magic, a world as beautiful as it is horrifying. Fate brings him together with his new loving mother and sister, and they face the trials together as a family. Follow their incredible story as they struggle to survive and create a better life for themselves.

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

With unmatched talent, but a fate sealed by a terminal illness, Jeong Yeon-Shin challenges his destined death for a chance to live.Set in a realm where elves and dwarves coexist with martial artists, this is the story of Jeong Yeon-shin, a genius fighting to extend his life against all odds.