I just finished one of the expansions and the plot was basically the same as SL.
Evil higher power guy mind controls a good lore character who becomes his evil knight to help him open the way to some 'core of creation' (that the main god used to create the universe) because he wants to unmake it and remake it in his own vision.
The west never got this game and those of us who have played it have had to use a fan/AI translation.
I understand that -evil lord guy going to some creation place to unmake reality- could be a trope, but combined with him mind controlling a good lore character who he turns into his evil knight pawn just like Anduin... it's more than a bit suspect.
Funny enough, the subsequent expansions for both games center around dragons (probably just a coincidence).