The supporting character's harem is very normal - Chapter 138 It seems she is... Lafien

The worst student of Westroad Academy. The disgrace of the Blake House. A new soul enters the body of Frey Blake, who couldn’t overcome his miserable life and chose death instead.

Jiang Pengji got something called the Court Intrigue Stream System.
System: “Your goal is to become the most prestigious woman in the kingdom (the Queen)!”
Jiang Pengji: “Okay, System. No problem!”
Years later, she met the target by becoming the most prestigious woman (the Empress).
Jiang Pengji: “Well done, no?”

In the beginning, when they all thought that she was “he”….

ML #1: We will be brothers for life!

ML #2: This time I’ll reluctantly let you have the #1 seat.

ML #3: I will properly repay royal teacher!

ML #4: Ah Rong is my closest little brother, I trust him.

Afterwards…

MLs: I’m seriously such a fool.

MLs: What do I do, I think I’m gay. I fell in love with my bro/rival/teacher….

Afterwards….

MLs: I’m straight! As straight as steel!

Note:
MC is a girl crossdressing as a boy, she knows how to fight, and naturally possess the gold finger halo from the author.

All the ML(s) is the same person, 1v1, sc, HE

- Description from Novelupdates

I possessed a character with an intelligence of 100 in a classic medieval fantasy land-grabbing game. An intelligence score of 100. That meant my predictions were always accurate. However, since I was physically weak and didn’t quite understand why that was the case, I thought it best to just live quietly. But then… leaders who began to recognize my ability started to become obsessed with me.