Quote fromSpeaking of old "aquaintences" comming back, who is going to be diablo this time? You supposedly permanently killed diablo in D2 when you put his soul in his soul stone and destroyed it but diablo III just wouldn't be a diablo game without him. Diablo can't be diablo without... well.. diablo. So who do you think the unwilling vessel is this time?
They could do something like they did with the pandemonium event, a lesser summoning him