Unbreakable - Chapter 174 - Got mixed up quick

A side story series featuring the girls of Kyoukai Senjou no Horizon.

Thousands of years ago, a small planet collided with Earth and destroyed the world. In five days, ninety percent of humans had been wiped out, leaving behind the last ten percent to earnestly struggle on death’s door.

Jinyu was one of those people who survived. Due to a special heredity trait, he could understand beast language. After the apocalyptic disasters, Jinyu had been living for a month with the few small beast brothers that he’d subdued. Previously, Jinyu had thought that he would live like that until he died. Yet, inexplicably, one day he opened his eyes to find that he was in a monstrous, lawless world that was full of vitality and life.

Jinyu’s transmigration into the future let him skip over almost one hundred thousand years. In the year 106825, beasts rule the galaxies and ‘pure’ humans are extinct. As the one and only ‘pure’ human left in the entire universe, Jinyu braves this new chaotic world to find a place for himself and thus begins to work at Beast Store number 138.

- Description from Novelupdates

Shi Jin was a desperate woman and just a pretty face in her past life. She was swapped at birth and brought up in a rich family, only to eventually die a horrible death.

Professor Kang lived the same day on repeat - same lectures, same coffee, same quiet evenings.Unremarkable in every way.That is, until the day he died trying to save a student.When he opened his eyes again, he wasn't in a hospital. He wasn't even human anymore.Reborn as the weakest of monsters - a slime - in a world where the strong devour the weak, survival is the only law that matters. But if clawing his way up means becoming the apex predator himself... well, so be it.