MTL - Vicious Male Partner is a Girl - ~ Work related

In her last life, she was miserable and ordinary. This time, she got into the fashion and was reborn in another world. She was still the same person… even with the same body and face. What was the point of reincarnation? A childhood companion? He always pulled her hair and made troubles for her? A handsome boy? The boy never looked at her and was 15 years older than her! A prestigious teacher? The teacher spent his days eating and drinking, coaxed, played tricks, and controlled others… Too scary and better run away? No no no, such a challenging life was bound to be wonderful! Now let me take you back to the 70s and live a fast life!

- Description from Novelupdates

After getting shot, Lucas, a serial killer, reincarnated into the novel world as a tragic villain with the same name, Lucas Ciffer.

Lucas Ciffer was supposed to be the Holy Kingdom's successor to the throne, but his demonic appearance and the powers he possessed terrified the entire kingdom. A white-haired boy with red eyes and pale skin, together with his dark powers, got persecuted and exiled by his own family. Not to mention that in the future he was destined to die by the hand of the hero.

Lucas fell from holiness, and, with the serial killer's bloodlust and knowledge of the future, he decided to prove the world right.

Yes. I could be a villain; no, in fact, I WILL BE THE VILLAIN.

Han Sheng Li is the Crown Prince of the Great Han kingdom. Since the age of fourteen, he mostly went to the wars with his father, Han Wenji, the great emperor of the Han Kingdom. He's the most favored child of his father but, is the cruelest and ruthless among all of his seven half brothers.