Clarisse

Clarisse is a boss character from Fire Emblem: New Mystery of the Emblem. She is one of the assassins working for Eremiya along with Reese and Legion.

While not much of Clarisse's past is known, it was hinted that she was born from a noble family, and her family had been murdered by the Soothsires, who had looted their house. She had been the sole survivor, and seemed to have lost her memories from the incident, where she had been found by Eremiya, though it is also hinted that Eremiya and Gharnef had a hand in her family's death.

Under Eremiya's care, Clarisse was trained to be an assassin, and grew up alongside Reese, Legion, and many other children, all molded to become Eremiya's puppets that would obey Eremiya until they broke. Clarisse soon came to view that only the strong would survive and the weak were meant to perish.

(Source: Fire Emblem Wiki)