RazeIn Beyond Divinity, the main character is a follower of the Divine One (who setup a group of Paladins to hunt down the remains of the Black Ring), who was pulled into another realm by a demon when trying to take down a necromancer. After getting soul-forged with a deathknight, the two escape prison and try to find a way to get back to Rivellon to undo the soul forge. As this happened to be where Damian was banished, along the way they see the aftereffects of his actions, and learn more about what happened up to that point. Of course Damian shows up at the end and manages to break his banishment (which is where D2:ED and its backstory take over the plotline). Zandalor was not in BD.
Yeah, that Death Knight (where are these sweet guys in D2? ;<) was teh Damian, as the "History of the Damned One Part VI" says:
Now that Nemesis was a barren land littered with ruins and Demonic encampments only, Damian waited patiently for one of his Black Ring followers to unwittingly set in motion his escape. The wait was long, but finally a necromancer on Rivellon summoned a Demon from Nemesis when he was being beleaguered by the Divine Order. The Demon slew all of the paladins and took with him the prize Damian desired: a prisoner.
In disguise, the Damned One freed the nameless paladin and convinced this unfortunate servant of good he'd help with the escape and devise a way to get back home. Together they travelled and combated the inhabitants of Nemesis, those loyal to a Damian incognito. At long last they reached the Raanaar citadel, where the paladin learned how to open rifts. And so, because a servant of the Divine wanted it, the Damned One could once more enter Rivellon...
Jodocus Lipsius, court historian.The one thing I don't understand - why BD always was called as spin-off? Because it wasn't about the Divine one? But D2 wasn't as well. Actually, I guess all these games are completely related and D2 is a sequel for BD as the latter sequel for DD.
Also, there is some mess with titles in Divinity Universe: initially, The Damned was the servants of The Lord of Chaos as Story.pdf (goes along with DD) tell us:
Powerful as they were, the Damned - as we named the wizards - were relatively few in number and could receive no further reinforcements.
[...]
After long isolation in their mountain fastness, the
Damned had re-emerged with a much larger army
Damned looked unnaturally young - none over
thirty - which served to confirm the rumor that the
Lord of Chaos offered eternal youth to his
depraved followers.
but in D2, we have the Damian, a reincarnation of the Lord of Chaos in physical form, called as The Damned One, which is weird, since he is not a servant of the Lord but the Lord himself.
Well, usual holes in game plots :P