Evolving into a Great Dragon From a Koi Fish - Chapter 21

This is a ‘rebirth’ story where Chen Rong, the heroine, finds her second chance at life after burning herself to death. Set in the Eastern Jin era when bureaucrats and their lofty yet equally hypocritical and oppressive ideas once ruled the empire, Chen Rong is made to use her past life’s experience to survive and hopefully find happiness this time around.

- Description from Novelupdates

When encountering demons, a young man with two horns on his head, red hair reaching his waist, and an extremely handsome appearance leads the demons to the front.

Youdou: Actually, I really don’t want to be a master of monsters. This profession is completely useless. My ideal is to become a magic stick…, bah, it’s to become a great onmyoji.

All the monsters: My lord, wake up, you are the leader of the monsters yourself!

- Description from novelbuddy

Flatten the Devil's Palace, eradicate the demonic cult, slaughter the demon lairs, sweep through the demon realm, dominate the heavens and earth, control the three realms, be the supreme master of the mysterious sect, master of the Nine Yin, the 17th head of the North Star Sword Sect, the Heavenly Fiend Lone Star, the Supreme Sword Soul, the Supreme Infinite Mysterious Heavenly Wishful Great Sword Patriarch... Also known as Iron Egg, known for the wild history of relentless killing.

The most successful businessman of his time, who started from being a homeless orphan, died indignantly because of being plotted against by his most trusted aid, his own brother.