The supporting character's harem is very normal - Chapter 513: Amleth and Catheryne

A seafood chef inexplicably transmigrated into ancient times. Even though he landed in a family with a nobility rank, and theoretically was supposed to be rich, the most valuable thing in the house is a grey donkey…
Su Yu stared at the sky helplessly; in order to support the family, he could only take up his old profession and go out to sell fish.
Unfortunately, the royal family selected concubines from both genders. Even as a poor noble, he had no choice but to attend…
DISCUSSION TOPIC: Will I be selected if I display my fish-slaughtering skills?
“Meow!” His Imperial Majesty shook his tail.

- Description from Novelupdates

I intervene in all events of the game. And take it away.

In the vast and boundless continent Cangtu, there were ancient sects governing the Ten Old Domains, unworldly immortal clans beyond the Blue Sky, and primordial demon gods dominating the dark abyss that together created a great number of brilliant stories over the long course of the history.

I, the protagonist, was just an ordinary NEET, but suddenly I was reincarnated as a tiny white snake in a fantasy world where legendary creatures and gods exist. Not only that, but I awakened in a cave as the offspring of a terrifying Medusa Serpent.Armed with only my human knowledge and my indomitable mental strength, I'm forced to use cunning tactics and rapidly evolving skills to survive against far stronger monsters and humans... So begins the survival story of a former shut-in with incredible willpower, living as one of the lowest-ranked beasts in a world of magic!ᆖMusic suddenly started playing in my head.I'd been waiting for this moment for so long.'Snakes! Assemble'....