In game 2883855 the last turn I possessed ended abruptly when I gained a Villa with University.
Looks to me like your own Enchantress charmed you unknowingly :o
In case this wasn't clear: You own Enchantress turned the University played as possessor into a cantrip, drawing a Curse. The Villa you clicked on, thinking it was time to gain a card with University, was the buy for that turn (I assume you have Autobuy on).
Enchantress of course - I should have loaded the game myself. ::) In earlier possessed turns, I had remembered that Enchantress was in place. In my defense, my opponent didn't get what was going on either. ;)
What made it difficult to catch though, is that the log is "destroyed" (scrollbar/earlier turns missing) after possessed turns, such that I couldn't see "buys a Villa" without reconnecting.
Stealth Enchantress strikes again!
Seriously, it's about time to put something in the log, and something in the play area, to indicate the effect of Enchantress. I think the cleanest might be to slightly modify the card's appearance that has been affected, but adding some sparkles (yes, sparkles) to it, or turning it into a pig. ;)