Theoretically here is how the game should be presenting the characters:
Belairon should be the High Mystic of Vhyr, Murvath (whose name changes depending on gender) should be presented as the archivist of the mystics. Do let me know, though, if you noticed any mismatching of those characters when you played.
Depending on the ending pathways you choose, Murvath either has a bigger or smaller role. Joining forces with Daggoras (or with the God of War) ends up cutting Murvath out of the plot for the most part, but he plays a bigger role in the ending if you betray the gods on your own, if you decide to liberate the gods, or if you lose the game outright.