Torement Soul going into NPC

I went to fight Vagan and a tormented soul found its way down there. It jumped into Vagan and after I defeated him the mark stayed with him. He did drop loot but I am unsure if that is normal for him(I am newer to the league and can not remember. If he doesn't then the loot from the tormented dropped and just the mark stayed on him.. not a huge bug but it is there