I play a Evil God in Otome Game - Chapter 2 - 1:God of Darkness

The genius pharmacist transmigrated into a pitiful farm girl’s body. Ignored by her own father, abused by her stepmother, and bullied by her stepbrothers. Her “twin” brother was given to distant relative and she went as the “extra” to live under someone else’s roof.

Luckily she possessed mad apothecary skills. Collecting herbs, plowing herb fields, formulating medicines and treating the ills, she refused to live an ordinary life as she slowly uncovered the truth of her real identify.

Inadvertently, she saved a dashing man who was in reality a big, bad wolf hiding under the skin of an innocent little puppy. He pulled out all his tricks: I have no other means to return your favor of saving my life. What say I repay you by marrying you?

- Description from Novelupdates

This legend tells the tale of the protagonist, Kuroki summoned to protect the demon king from the hero.

Kuroki, unbeknownst to him, suddenly came to another world. He was summoned by the demon king, Modes. The territory which the demon king overrules was in the midst of being destroyed because of the hero. He had no choice but to bow before Kuroki.

“Please save us, Savior Dono!”

Kuroki nodded, deciding to save the demon king due to an unexpected turn of event.

What would you do if you were reborn in the world of Battle Through the Heavens without a distinguished background or an elder in your ring and just a decent talent?Luckily, Xiao Ming has awakened the Life Simulator System![The Life Simulator is on]......[You have experienced an ordinary life.][Elements are being chosen.][Currently available: Green Lotus Core Flame, Flame Mantra, Woeful Poison Body.][Please choose one.]Every seven days, he can choose to extract one of the elements from his life simulation.In this way, Xiao Ming began his ordinary life.

What is a genius? Capable of comprehending any battle skill regardless of the skill itself and sweeping away the bottlenecks while cultivating a new technique; this is a true genius! He Yiming was originally an ordinary youngster in the He family’s estate with not too extraordinary aptitude in learning martial arts.