I just think we should go back in time in DS. Back to the point where the Dragon Titan had been awakened during the war, and we would become soldiers for one of the sides. The main villian might be tampering with the timeline, so you go back to stop him/her. Otherwise, it could cause your actions in the past against Malistaire to mean nothing- therefor causing a rip in the time-stream and possibly destroying the spiral. Which would probably be bad.
Anyways, you would have to fight to end the war, and eventually battle the Dragon Titan itself. Maybe not in it's normal form, but as a draconian guise.