Kuro to Kuro to Kuro no Saidan [KURO3] - 黒と黒と黒の祭壇 -蟲毒-

Someone posted this, and there's barely any information that I can find so I'm gonna go ahead and paste it here.
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It's a revenge story.
Basically a prince got thrown in a prison, he gets to have the opportunity to have his revenge on his family and god.
He does so by imprisoning and "training" his little sister who is also a holy woman for his objective.
It could be considered a training/rape game but it actually has a pretty good story full of references of the old testament.