Hijiri Houshou Hana Saint Lime VN: VeasTube Eroero Haishin Edition 2

Saint Lyme is captured by the Vieste army. To finally break her heart, which still stubbornly resists, the monster Devil Beetle and his subordinate - the evil magical girl Blood Cherry - come up with a new cruel plan.
- “Please do whatever you want with the defeated and pathetic Holy Cherry, without any restrictions...”
Lime is forced to observe with her own eyes the depraved and vicious figure of the heroine whom she idolized and whom trusted. After this, she is no longer able to suppress her secret desires and finally completely surrenders to the Beetle. A masochistic magical girl who voluntarily submitted herself chooses the same path as her brother... no, already her sister. So she is reborn into a new heroine of evil. Like her brother (or is it her sister?) who was defeated by the Devil Beetle and who was never able to return to male form, Saint Lime also falls into complete corruption.
— “At this time, I officially announce that I renounce the title of the heroine of justice.”