World Apocalypse: Apocalust - Chapter 11: Training I

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

- Description from Novelupdates

After transmigrating to the Great Desolation world, he became Dijun.At first, he did not want to be this demon emperor, just wished to be a carefree innate sage. However, appointed by the Dao Ancestor Hongjun, he had no choice but to take on this heavy responsibility.As for the war between the Witches and Demons, Dijun is not interested at all, he only wants to lead the demon clan in building the Great Desolation, and win the favor of heaven and earth, earning virtues and fortune.And the Zhou Tian Star Array, was it created for battle? Dividing day and night, establishing the four seasons, transforming chaos into innate aura, benefiting the Great Desolation, this is the true purpose of the Zhou Tian Star Array.With virtues and fortune upon them, who dares to provoke the demon clan?Under Dijun’s leadership, the entire demon clan continually contributes their strength to the construction of the Great Desolation.

Eren Idril died as an old, decrepit, and piss-poor adventurer by the maws of a D-Rank monster. He had a lot of unfulfilled dreams and desires that couldn't see the light of the day after the light in his own eyes died down.

But fortunately for him and unfortunately for the world, that wasn't his end. Eren was somehow dived back in time when he was a mere teen, attending Lionheart Academy for adventurers.

When life gives him a second chance, Eren decides to exploit it to its fullest. Experience his vile deeds as he partakes in them without feeling the slightest bit of hesitation.

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