He will probably rape the rest of Touhou (minus Rinnosuke)though.
Well, if you look at the list...
Non-rape-able loli ================== Rumia Cirno Mystia (Isn's she one?) Wriggle (Well, it's yet to know whether it's a he or she...) Suwako Tewi Remilia Flandre Satori Koishi Shikieiki Suika
Non-rape-able because it's damn too dangerous ============================================= Yuuka Otsuho Mokou Keine
Easy target =========== Reimu (Donation is the key to victory...) Eirin (Just be a test subject?) Tenshi (She will ask for it. Pronto) Hijiri (Rance will most probably aim for the eightsome. Though he will be forced to monkhood...)
Not even effort neccessarily- Just different approaches: Mokou x Keine-Go for the threesome! Yuyuko: Food. nuff' said. Utsuho: Radiation shielding. Yuuka: He'll Find a way.