An interesting tag on pixiv
東方悪堕ち
Evil Conversion Touhou...if you can think of it, there is Touhou fan art of it.
Apparently the posters never bothered to add a plain old 悪堕ち tag so some of these are fairly new...
http://www.pixiv.net/tags.php?tag=%E...A0%95%E3%81%A1
Mostly inspired by the Evil futa-succubus Reimu meme...not necessarily the greatest stuff but its content.