MTL - The Head of My Family is Number One In the World - Chapter 401 Tongyou! The original demon!

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.”

Eight hundred years ago, Xie Lian was the Crown Prince of the Xian Le kingdom. He was beloved by his citizens and was considered the darling of the world. He ascended to the Heavens at a young age; however, due to unfortunate circumstances, was quickly banished back to the mortal realm. Years later, he ascends again–only to be banished again a few minutes after his ascension.

Now, eight hundred years later, Xie Lian ascends to the Heavens for the third time as the laughing stock among all three realms. On his first task as a god thrice ascended, he meets a mysterious demon who rules the ghosts and terrifies the Heavens, yet, unbeknownst to Xie Lian, this demon king has been paying attention to him for a very, very long time.

- Description from Novelupdates

A side story series featuring the girls of Kyoukai Senjou no Horizon.