also i have some ideas
NPC Succubus-teacher - can teach you a new spell: milk spell (lust damage every turn and add some new scenes with female NPCs)
Sex EXP - everytime you win against NPC and have sex with them you will gain some S E X P, S E X P will increases S L V L, but it can be just cosmetic, because i thought it will change some scenes with NPC (0-4 SLVL - you ending first, 4-9 draw and 10 will be a looong ride) dont ask how i came with that idea