Dating sim loading: My girlfriend is a cunning young lady - Chapter 10 - 8. Guide completed

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

Shaymon, the man who has achieved the apex of dark magic, is framed as being a Demon King and is killed.

A Hentai World is a Dangerous Place, Especially if Your Best Friend is a Hentai Protagonist and You Are a Trap.

A wicked mother one day brought home a girl. The child was the hidden legitimate daughter of the duke, the heroine of [The Duke’s House Has Three Sons and One Daughter] Loretta. I was Melody, the villainous girl who tormented her and was condemned along with my mother. Not wanting to die like that, I decided to start treating her well now. I personally fed Loretta, put her to bed, and played with her. And then her reaction was…? “I want Melody to marry me!” Caught off guard by her endless affection, I too ended up entering the duke’s family, “I’ll stick right by Miss Melody’s side.” And there, it seems I’ve met a young lord who’s an even bigger ‘Melody fool’? All I did was be kind to survive, but why am I being loved…?!