Rusalka Schwägelin (ルサルカ・シュヴェーゲリン)
Background
Despite being cunning and crafty at her core, she is playful and flirtatious on the outside, making her a very dangerous individual to associate with. She also has a fondness for torture and is known to be extremely moody. Though essentially not a fighter, her cruelty rivals even Wilhelm's.
(Source: VNDB)