Black Rose

Black Rose is a powerful unicorn mare who was Terrato's student and ex-lover. Due to their relationship, he ended up teaching her more than a magic than she was supposed to know, which ended up being the 6th rebellion. She became almost as powerful as an alicorn, and decided she wanted to assassinate Celestia. Terrato was forced to kill her. However, near the end of The Breaking Point, she survived and manipulated Terrato and Celestia into fighting each other and committing the 7th rebellion, then stole Celestia's powers. She is the main antagonist through much of Reckoning, and intends to siphon power from the Blasphemous Rift to gain Oceanus' power.