There's No Love In the Deathzone (BL) - Chapter 682: Side Story 3. Stellar Blossom - 17

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

Ye Xiao was a superior cultivator in his previous life. The three factions of the realm kill millions of people every time they attempt to seize cultivation resources. Wealthy towns turn to wastelands in just a single night. They cover up their crime with an assertion that the towns were suffering from pestilence and disasters.

They forcibly hold all the resources for cultivation, monopolize all valuable practice materials, and keep outsiders from cultivating so that only their three factions could cultivate in the realm. Ye Xiao declared war against the three factions in retaliation for their actions. He fought alone and ended up dying in vain. However, he is reborn into the mortal body of a 16-year-old boy. He will use the powers he cultivated in his last life and slaughter his way back into the Realm. The story begins!

- Description from Novelupdates

After transmigrating to the Great Desolation world, he became Dijun.At first, he did not want to be this demon emperor, just wished to be a carefree innate sage. However, appointed by the Dao Ancestor Hongjun, he had no choice but to take on this heavy responsibility.As for the war between the Witches and Demons, Dijun is not interested at all, he only wants to lead the demon clan in building the Great Desolation, and win the favor of heaven and earth, earning virtues and fortune.And the Zhou Tian Star Array, was it created for battle? Dividing day and night, establishing the four seasons, transforming chaos into innate aura, benefiting the Great Desolation, this is the true purpose of the Zhou Tian Star Array.With virtues and fortune upon them, who dares to provoke the demon clan?Under Dijun’s leadership, the entire demon clan continually contributes their strength to the construction of the Great Desolation.

There was a Senior Brother and a Junior Sister. One of them was transmigrated to this world and had cheats while the other was the reincarnation of a Great Emperor.