Bog Standard Isekai - Chapter 49Book 4.

To correct the mistakes of his past, a young man is forced to narrow the space between science and witchcraft, as he ventures on a quest to save his world from complete destruction.

In the depths of a newborn universe, a cultivator takes advantage of the abundant energy to refine himself a treasure. But after 14 billion years of refining and quite a few more to go, he decides to entertain himself by releasing countless systems and watching how the creatures of this fledgling universe handle them.

On Earth, a young man, lost and confused about what to do with his life, sits in a park and looks up at the night sky. A shooting star, a wish and a bang. When the boy finally wakes up he hears a sound, "assimilation complete. Launching System. Welcome to the Midnight Inn. Host Designation: The Innkeeper."

After I defeated the Demon King, I was executed for false accusations by the heroines.When I came back to life, this was the first thing they said.“I know it’s shameless, but would you help us one more time? Without you, the world will be destroyed.”…Would you help them if you were in my shoes?

A botched rescue mission with an unknown objective cost Zhou Yu his team members, while leading him progressively closer to the multinational biotech corporation Juli’s research core.

In order to protect his botanist younger brother Zhou Qing, Zhou Yu accepted employment under the Juli Corporation, and is dispatched to a parallel world—Nibelungen.

Nibelungen’s biological systems are completely different from the world Zhou Yu is from. To live in this place, Zhou Yu must follow three great laws:

The first law, fear is the sign of the hunted, so you must never show fear.

The second law, the more beautiful an organism is, the more dangerous they are. Do not approach them, and do not trust them.

The third law, do not be misled by the mimicry of S rank organisms. They understand your mind, and they know how to entice you. Always remember that they have no human emotions or love. All humans are no exception to them.

Finally: We wish everyone can live happily in Nibelungen.

- Description from Novelupdates