It is possible, that Dunkalzahn is merely seeking his corrupted brother in a final attempt of redeeming him, or he is about to become a new Passion for the modern age...
Or he's dead and its all a mad grab for power...
of course the Dragons taught the early elves that they could progress throught the circle of life and then "ascend" into the metaplanes and live eternally... sort of what the Great Ghost dragon did, and what Dnkalzahn did to survive his "death" for a little...
2 cents.