クリスタ

Christa is the third wife of Karlheinz and the mother of Subaru.

Christa only appears in Subaru's dreams and flashbacks of the time when he was with her. 

Due to her beauty, Christa is lauded amongst the vampires as 'White Rose'. That led Karlheinz to desire her. She was forced into becoming his bride and raped - of which the later led to Subaru's birth. It is also revealed that Christa had a brother whom she loved very much.

As a result of these series of incidents Christa, mostly a shell of her former self, became ill. She is described as having a ghost-like presence. 

It is seen that she hate Cordelia very much. She was going to get killed by Cordelia but Subaru rescue her. Unlike the other monthers, it is seen as well that she extremely loved Subaru and cared about him very much.