The supporting character's harem is very normal - Chapter 479 Pathogens

There is an ugly beast that violates women in prison.

A treacherous beast that is feared and called a “Butcher”.

That’s me.

I was once a human but now I can’t even remember my own name.

I can’t speak, and I don’t understand a word they say.

It is in this deep loneliness that I am pouring my essence into the women everyday.

I pour my burning rage into them.

Over and over again, until they conceive.

From morning till night. Until the women’s souls withered.

To show them that I’m an excellent stallion and an obedient domestic animal.

But my soul has not perished yet.

I will break free from this prison soon. And when I do, it will be your last.

Every human who betrayed me, every demon who altered me, I will trample down like an ant.

And it won’t stop until I’m satisfied.

The dawn of the beast is near.

In the turbulent era, the world was under the reign of cunning careerists. A young man named Mu Feng grew up in numerous battles and unceasingly made earnest efforts to stand on his own feet.

His father was murdered, and two hundred thousand of his people were slaughtered. Mu Feng accidently obtained the Sacred Book of Asura, and then he embarked on his journey of revenge with fierceness and blood!

Killing and blood proved his love for family and his people!

He was the almighty Asura!

- Description from Novelupdates

He Lang died by his own hands for the sake of his imperial younger brother’s ambition, whom he loved. He was offered to be reborn in exchange for giving up his past romantic feelings. Reborn without the burden of his romantic feelings, he brings with him a manual to new worlds. He wholeheartedly followed the instructions of the manual to complete the tasks, not knowing that the originally slag gong was blackening…
He pleaded to his affectionate Emperor brother to release him, he pleaded to the paranoid prisoner next door, but until the end he remained baffled.
In the end, he discovered that the full name of the manual was – “Slag Shou Cultivating Manual”
Σ (っ ° ° °;) っ!

- Description from Novelupdates