Klaus

Klaus ( ク ラ ウ ス, Kurausu) was an archdeacon and the personal assistant of the pope. Klaus took custody of the injured Northern Crown Katya waiting for the right time for her to met the pope Saga. One night Katya tried to enter in the private room of the pope after listening strange rumors and seeing some blood inside but was stopped by Klaus that barren her to enter. Instead Klaus himself enters and was quickly killed by Saga but thank to his death Saga temporarly regains his good personality and permitts the escape of Katya.

Behind the scenes
Possibly this characters was insipred by the anime-only character of Arles, that was very similar.