Kill to evolve: A system that demands blood - Chapter 1: Kill to survive

Lingyun, a fierce and savage cultivation genius takes over a dead teenager’s body. Coincidentally, they are both named Lingyun. Set in a alternate version of the 21st century, teenager Lingyun has been killed by someone with a grudge.

- Description from Novelupdates

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

Even though Gu Yunxi was created from the accumulation of the resentment of souls, there was not a bit of ruthlessness nor cruelty in his nature, only a desire to cultivate. Just as he achieved his human form, he was sent to reincarnate. Under the control of Heaven, he experienced life after life of suffering, dying a terrible death every single time. After thousands of reincarnations, thousands of terrible deaths, he finally accumulated enough power to escape from the Laws of Heaven. He swore to get revenge on this blind Heaven’s Law that’s unable to differentiate good from evil.

So what if it’s the Heavens? He will stir up the rights and wrong, the good and evil!

You want me to accept this life and die, but I just won’t! I want to live, to rebel against the heavens, to reverse this joke of a destiny!

- Description from Novelupdates

Chen Zhao can summon demons and see Death.