Soukou Seiki Ysphere: Ingyaku no Sennou Kaizou

"Soukou Seiki Ysphere: Ingyaku no Sennou Kaizou" is a hentai series about an anti-human organization called Omega attempting to conquer the world. The only ones who can stop them are a group of magical girls, Esphere, fighting for justice, but when captured, they undergo brutal brainwashing and sexual torture that push them to the brink of sanity.