Hah, funny coincidence. I was just re-reading FGO's CCC event summary and it was Zepar that turned Kiara back into a super lust demon boss. His thing in Ars Goetia is inducing love and lust, so I guess it's accurate.
I'm sure all the teachers are just relieved that Okazaki has a somewhat stable future now instead of dropping out and becoming a bigger problem to society.