This story is called "I Changed the Hearts of the Villainous Family Forever" ENJOY

The villainous family consists of Nathaniel Natalia, who is the northern Duke of the Etelldia kingdom. He is a ruthless, powerful tyrant. Ruling over the northern side of the kingdom with an iron fist. Slaying anyone who dares get in his way with his sword. The Dutches, Victoria Natalia, who is known as the black flower of the empire, is an expert with poison and is very cruel. They also have two children of their own. One son and one daughter. They're twins named Raphael and Rachel Natalia. Raphael is great with sword and is very intelligent and is the leader of the Dark Moon Knights or DMK, but he is very cold-hearted. Rachel is the leader of the magic tower and is the greatest mage in the kingdom. She is selfish, not caring about anyone, but herself.

You are (whatever age you want) rn and are standing in front of the graves of your parents, Kasper August and Bella August. Who both died a week ago due to being attacked. While members of your family wep and say how young they were to lose their lives. You look at your parents' bodies with a blank face. No smile. No light in your eyes... just blank. Bella was the younger siser of the Duke, Nathaniel Natalia. So, two days later, you were under the custody of your uncle, Nathaniel Natalia.