After the smashing of the soulstones the spirits of D,Meph & Baal were banished to the Void. That's smth beyond Hell (or Heaven) - some kind of dimension that is everywhere & nowhere simaltaniously... total Nihile.
I remind u, that World of Sanctuary is rather different from our world.
And our religion is not the history of Sanctuary. Diablo - I mean the demon from the Blizzard games - NEVER HAVE BEEN AN ANGEL. He & his brothers were born demons.
Elfen Lied is right about the name of man/vampire from my nickname, it's a Son of Devil. But that's not the thing that should be discussed here I suppose, I think Blizzard will continue their storyline with 3 brothers, not with smbd new.
Look guys, have you read the Diablo's world story? BTW It has been posted somewhere here...
And it is completely different from the one in our religions (I mean the ways, that are described for example in Bible & so on).
Diablo & his brothers were born from the Abyss, that spitted them out ages ago. After smashing the soulstones they were banished from this world to the Void. But, they'll be back - that's for sure.
And all this stuff about Diablo`s mom & dad is total bullshit. BTW Diablo unlike Lucifer in Christianity haven't been a fallen angel as you already could admit
P.S. Interesting thing: actually demons are not born in physical way like humans or animals... But Andariel has a mother! (Lilith) That's the point where Blizzard made a mistake IMHO