The supporting character's harem is very normal - Chapter 410 Sacrifice

Leon Walker, the world-weary genius of modern world, is killed in a freak accident — the notorious Truck-Kun makes an appearance. Death is only the start. He finds himself reborn in a new world, Galvia, reincarnated into the strong but failing body of Duke Leon Moonwalker, one of the only three Grand Dukes of the Moonstone Kingdom, a minor but strategically powerful kingdom within Galvia. As Leon attempts to understand his new world, a strange voice resonates in his head. “Supreme Spouse System Activated.”.

After crossing over to another world which seemed to be a fusion between many anime worlds, The Fantasy System was unlocked for Mu Fan. After finishing the tasks given by the system, Fantasy points are given which allows him to gain access to the Fantasy store that was full of daily talents and more.

Yuuki Asuna: You know how to cook a lot of dishes. Can you teach me?

Sagiri: I don’t know anyone called Eromanga-Sensei.

Many more characters and interesting plots await us.

- Description from Novelupdates

Mu Zhi’an transmigrated into a world of immortals and became a supporting character destined to be a stepping stone for the protagonist. He originally wanted to befriend those heaven-chosen protagonists, but when Mu Zhi’an turned around, he discovered that the girls surrounding him were either the protagonist’s childhood sweethearts or fiancées.Most inconceivably, those girls who should have liked the protagonist all fell for Mu Zhi’an, this supporting character. Looking at the heavenly beauties beside him, one after another, Mu Zhi’an had a bold idea. He resolved to get rid of the protagonist and turn the tables to become the master himself.After finally defeating several protagonists with great difficulty and obtaining a large amount of resources, in order to enhance the girls’ strength, he shared the abundant resources with the girls around him. He originally thought that with the enjoyment of so many resources, he would surely be able to prove the Dao and become an emperor in the future, transforming and ascending as an immortal. Until one day, looking at the rolling tribulation clouds in the sky and the several empress characters reborn in the lightning tribulation, Mu Zhi’an’s eyes gradually lost their luster as he muttered, “I’m so foolish, really… I thought that after getting rid of those heaven-chosen sons, I would be the new protagonist of the world and become a powerful immortal in the future. But I never thought… it turns out they were the real protagonists all along.”

At home, she was invisible; after marriage, she was a decorative vase; in the end, a sea of flames buried her, and not even her corpse remained. This is the portrait of Han Yuxi’s previous lifetime. Given a chance at rebirth, she strives to improve herself, wishing only to no longer serve as a foil or a pretty face. Then, she will seek out an exemplary husband and live a life of peace and prosperity. Alas, things turn out contrary to her wishes—she marries a man who bears a blood feud and hatred as deep as the sea. She turns the world upside-down, but her road to happiness is strewn with setbacks and the sweetness that comes after bitterness.