Ziz's adaptation of Taimanin Murasaki (or Hell Knight Ingrid), the third Taimanin Asagi game by Black Lilith.

Ingrid, a once feared and powerful Knight has fallen into the hands of a madman who has enslaved her body and mind. Forced to do the sexual bidding of her master with no ability to fight back she is broken and raped endlessly.

(Source: hanime.tv)