Re: villain hentai games
Hmmm...
English:
Overwhored- Definitely comes to mind immediately, clearly influenced by the Overlord series of games (where you play as the evil overlord), but with rpg gameplay and sex. Enough variety of characters that some will probably be to your tastes (and some probably won't). Drawn graphics. RPG maker.
Harem (evil route)- You've got mind control powers, and can use them as a semi-hero, or as a complete and utter bastard. Evil route can be evil at times. 3dCG graphics. Rpg Maker
Evil Inc.- Rags game available on the Hypnotics Collective (mind control based forum. Has a fair amount of stuff that may interest you). You play as a super villain with mental powers. Unfinished, but has a couple hours of content, still being worked on. Generally well photoshopped pictures/short vids. Rags.
No Haven- Another Rags game on the collective. You play as the leader of a band of slavers. Bit of a learning curve, time/resource management is a must. Fair amount of stuff implemented, mainly sandbox play currently (main story isn't too far along). Assorted free use art. Rags.
Mindshift Pt1- Yet another Rags game on the collective, you're learning to use hypnosis powers. Pt 1 is primarily setting the stage for the unreleased pt2 (expected sometime this summer I believe), where you can end up with good, bad, and villain endings depending on your actions. Well photoshopped pics. Rags.
Japaneese: (quick glance at some of the recent ones)
http://www.ulmf.org/bbs/showthread.php?t=26846 - You play as merchant who hires female guards to guard your caravan. You also have a deal with some bandits to pretty much sell them said guards. See the thread for more info. Haven't played it.
http://www.ulmf.org/bbs/showthread.php?t=28884 - You play as a tentacle monster. Standard dodge the pixels gameplay. Fairly short.