The supporting character's harem is very normal - Chapter 451 Ancestor’s Oath

Kai is the hardest working warrior in his generation... and the unluckiest. In a world where most people receive magical skills, classes, or cultivation, Kai has nothing but his wits and his strength. His only choice will be to forge a new path against fate, no matter where it takes him.

Savage monsters pour endlessly from the wasteland, threatening the survival of civilization itself. They say that human strength isn't enough and only those gifted with destined powers have a chance of making a difference. Kai is hungry to fight in that war, to be someone who matters. That hunger will take him across a world stranger and more terrible than he could possibly have imagined.

‘I want to travel to a place unknown to the many…’

It was a passing wish to the weary and tired Eugene and she’d not think it’d ever come to pass… but it did.

She opened her eyes and found she was sent to a novel-like world she wrote in passing and became Jin Anika, the scorned queen notorious for her ruthlessness and undeserving of her status.

Queen Jin only sought and desired to see the destruction of this world — the villainess who met her untimely and miserable end at the hands of her husband, Kasser, the reigning king of the Fourth Kingdom.

While struggling to survive in the unknown world, King Kasser visited Eugene and demanded that a contract be fulfilled and come to fruition.

“Three years ago, we made a deal.”

It turns out the Queen was under a contractual marriage with King Kasser. The ultimate price? To bear him a child.

“A… a child?”

“Yes, my successor.”

In the Interstellar era where the strong are king, soft and cute species are almost all extinct.

Tu Mianmian, who crossed over, was given a ruthless Duke husband, a husband who could destroy Mechas in minutes.

As a lop-eared rabbit who had just refined his human shape, he felt weak, pitiful and helpless.

So, he resolutely ran into the entertainment circle, relying on his sky-defying appearance to garner large amounts of fans from interstellar society, including his own gong/husband.

It was night, and the Duke who was going to improve the relationship between husband and wife walked to the door and saw a fluffy lop-eared rabbit lying on the sofa…

When Tu Mianmian found himself sleeping beside his gong with his rabbit body stretched out, he scared himself. Sitting up in shock and dazed, he unconsciously stomped the Duke’s mouth. Shivering, he retracted his rabbit paw, but was caught by his gong with a cold face.

Tu Mianmian: …I, I, I am willing to cut off this rabbit’s paw!

Before he could finish speaking, the iron-blooded Lord Duke approached his mouth at the speed of light: Chuu~~ ( ˘ ³ ˘)♥

- Description from Novelupdates

To take a dragon's hoard is to challenge death.The greatest of the sea-drakes wakes, curled on his silver throne; but there is no silver. His hoard is stolen. He rises, screaming, and chases the thief to the ends of the world—only to be shot from the sky.But dragons do not die easy, and never one with such festering hatred. A dungeon core rises from his corpse.If he intends to survive so near the cove of pirates that slew his past self, he'll need to master his powers—and quickly. For these pirates are dragonslayers; they won't be felled by mere mushrooms or spiders.Beneath the lawless Calarata, the young dungeon core will have to fight to survive; and one day, he will return death to the man who killed him.