Mariah

Mariah is a minor character who appears in Dishonored 2. She is one of the few witches loyal to Delilah Copperspoon encountered during the mission The Clockwork Mansion.

Dishonored 2
At some point after Delilah's coup d'état, Mariah and two fellow witches, Heather and Kai, were assigned to Karnaca by an order issued from the new Empress herself. Mariah was tasked to kill the protagonist, with the promise of a reward and a portrait personally painted by Delilah in a case of success.

She can be found patrolling the exterior of the Aventa Station with other two witches after rescuing Anton Sokolov from the Clockwork Mansion, seated on the guard post. It's heavily hinted that she, along with her colleagues, slaughtered the guards who were patrolling the area, whose lifeless bodies are scattered in the plaza.