Vaylin

Vaylin is the secondary antagonist in Star Wars: The Old Republic - Knights of the Fallen Empire.

Overview
Vaylin is the daughter of Valkorion and Senya Tirall, and the younger sister of Arcann and Thexan. Even as a child, she was a gifted and powerful Force-user like her father and twin brothers. When her parents saw that she was becoming unhinged and evil, Valkorion mentally locked away her powers, but that only made her even worse. When Valkorion was finally killed, Vaylin was freed from her father's control and ruled the Eternal Empire with Arcann, serving as his top enforcer.

Trivia

 * Vaylin is similar to Azula from Avatar: The Last Airbender: They are psychopathic princesses and child prodigies who were raised by tyrannical fathers. As time went on, they became even more deranged and are willing to kill to get what they want.