Tomodachi no Imouto ga Ore ni Dake Uzai - Volume 1, Epilogue

One day, I was given the mysterious power of Hwanmong.

When Fang Yuan was transmigrated into a world where Gu Breeder was the main profession, he found that he was not gifted.

Not only that, the Gu in his body could cultivate on their own.

[Your Iron Skin Gu has trained profoundly and has achieved the Gold-grade!]

[Your Bloodthirsty Gu has begun to multiply itself into a swarm of Bloodthirsty Gus!]

[Your Sunlight Gu has been absorbing the power of the sun for years and has gathered the Truth Flame of the Sun!]

[Your Drunken Gu has evolved into a Soul-reaping Gu. Your control over it has risen by 100 folds!]

[Your Flying Sword Gu was hurt in battle. Amid its desperation, it has evolved into a Sword God Gu!]

“Heck, even Gu undergoes involution as well now?” Fang Yuan let out a sigh.

You Liangxing would never open the speech function in game.
That was because his voice was…
Particularly! Kittenish!

But there was one day, he queued up with a teammate who had so much to say that they may as well explode. Vexed to the point of no return, he contributed a voice that was capable of splitting heaven and earth, “Don’t BB.”
The other party who was being scolded stilled. In the ensuing silence, he suddenly let out a long, relishing… Moan.
You Liangxing: “…..”

Later —
He realised that the person was a great god,
Much later,
Without him realising,
He became the great god’s royal healer.
…. And also his boyfriend.

- Description from Novelupdates