Another Boss character I did inspired from the world of Sekiro: Shadow Die Twice.
She's was skilled warrior and one of the strongest guard in Ashina. While she was out defending the Castle, bandits managed to break into her house and all her children were ruthlessly slaughtered. After finding out what happened to her children, she was enraged and she single-handedly attacked the bandits' camp. Unfortunately she was stilled captured and brutally murdered.
She died near an ancient cursed weapon, and her body and soul were corrupted. She became immortal but she can't move too far away from the weapon's location and that is her curse. Anyone who trespasses are killed. She likes to collect her victim's arms and legs because she can't forget the devastating memory of seeing her slaughtered children without their limbs.