I guess it's a random chance to meet a futa bandit girl or something? Or is is a special encounter?
The Drain Kiss is the only spell I get of Rinny, and if I ask for magic lessons she tells me "maybe later".
Also, even with fertiltiy pills, Rinny cannot impregnate the MC for some reason
As far as I can tell, there is no content besides Transylvania and roaming around New Ark city ATM. The Science Tower, Flesh parasite base, Desert, Milk factory, etc are not available yet.
EDIT: Nevermind, got it