Originally posted by: Eeezee
What's left to do in the story? You already killed the 3 demons and destroyed their soul gems. It's over; Diablo can't come back.
I can think of one thing: Tyreal.
Taken from the Wiki entry for LoD: "
Baal, the Lord of Destruction, is seeking the Worldstone, a massive crystal of great energies, built to prevent the High Heavens and Burning Hells from consuming the mortal realm completely into their respective folds. It is the source of all the Soulstones and their powers, so Baal wishes to obtain it, corrupt it and complete his brothers' plan to conquer the mortal realm and use it as a staging area to besiege the Heavens in the endless war between the two."
At the end Tyreal mentions that the Worldstone is already corrupted and that the defeat of Baal is insignificant in face of what could happen by destroying the Worldstone, but Tyreal risks it, and before doing so teleports the mortal hero (whatever race Blizzard thinks is the one responsible for Baal's defeat out of the seven available) to a "safe place" where the effects of the destruction, whatever they may be, shouldn't be too great.
In my opinion Tyreal gets corrupted.
My reasoning behind it is because when you kill Baal you can clearly see his spirit escaping his body and going inside the Worldstone before Tyreal destroys it in the final scene. Basically I think that Baal takes Tyreal's body/mind under control and makes Tyreal the new and much powerful Fallen Angel, in the same way that Izual got corrupted by Mephisto (I think, or was is Diablo... not sure). In a potential Diablo 3 there has to be something about the result of the Worldstone's destruction, further corruption of the mortal realm, the war (maybe) between the Burning Hells and the Heavens (maybe the Pandemonium Fortress will play a role there) and obviously Tyreal. If not then it shouldn't be called Diablo 3.