FIRESTORM IS THE CULPRIT 95% OF THE TIME, TRY NOT USING IT FOR 10 OR 20 GAMES THEN PLEASE WRITE BACK HERE WITH RESULTS.
Sorry for caps but I play with roughly 15 people regularly, we all had the constant issues with the key not dropping until we quit allowing Firestorm in our games and now we only get hung up from Templar Assassins occasionally.
It seems that if an enemy is currently knocked to the ground by Firestorm and killed, it can occur. I do not know if an ally needs kill it or what exactly must transpire. If I pin down the exact mechanics I will post.
