The supporting character's harem is very normal - Chapter 125 I think he will save you

Inexplicably reborn in the year 2003, having failed terribly in his previous life, the prevailing concern with Xu Tingsheng, that stands above all else, is none other than her. But alas, he is just months away from entering university, while she is but in her first year of junior high… Regarding this, all he can do is wait silently…for now.

Short, rich, and handsome, Lin Feiran was always the center of attention. But after transferring schools in his second year of high school, he discovered that his limelight was snatched by his Adonis classmate, Gu Kaifeng.

'Did I reincarnate as the First Born son of a noble???'Jack was reincarnated as Jack Kaiser. Firstborn son of Alaric Kaiser, the strongest duke in Elysium. Born and destined for greatness. Or so they said.In a world ruled by Magic and Martial Arts, where talent determines everything, Jack's future seemed guaranteed.Until an unfortunate hunting trip left him in a 10-year coma.A system awakens within Jack. Granting quests and accelerated progression, Jack realizes he might have a chance to reclaim his destiny.In a world of dungeons, monsters, a political challenges, Jack will rise to his new title and become the Strongest Kaiser in history.

This novel is also known as Gu Daoist Master

Humans are clever in tens of thousands of ways, Gu are the true refined essences of Heaven and Earth.

The Three Temples are unrighteous, the demon is reborn.

Former days are but an old dream, an identical name is made anew.

A story of a time traveler who keeps on being reborn.

A unique world that grows, cultivates, and uses Gu.

The Spring and Autumn Cicada, the Venomous Moonlight Gu, the Wine Insect, All-Encompassing Golden Light Insect, Slender Black Hair Gu, Gu of Hope…

And a great demon of the world that does exactly as his heart pleases!

—

*Gu (蛊) referred to poisonous insects in various cultures in South China while in folklore Gu spirits could transform into all kinds of species.

- Description from Novelupdates