Found an interesting corruption scenario between two ANIM games: Tokumei Sentai Yuzurenja and its sequel Tokumei Sentai Sirenger.
Eroge focusing on Sentai Heroines seem almost required to have some form of corruption.
I found Yuzurenja a while ago though I really wasn't impressed by the art or the events, Justice Blade had me spoiled so I wanted straight forward evil Sentai gratification which isn't really all that clear in the CG's. To be honest Sirenger didn't fare much better until I realized that the villainess in Sirenger were the Heroines in Yuzurenja who apparently failed their mission and were corrupted...
CG links. Lots of tentacles related stuff...
特命戦隊ユズレンジャー
Tokumei Sentai Yuzurenja
http://rapidshare.com/files/26167562...renja.rar.html
特警戦隊サイレンジャー
Tokumei Sentai Sirenger.
http://rapidshare.com/files/93176813...enger.rar.html