At the end of the war, Davis was, without a doubt, the single most powerful individual on Pangea.  He was largely seen as the key player in the wars success, and had supporters in all races and most groups.  With the previous emporer and his family having been killed early in the war, and no time to appoint one during the war (instead there was a regent), the assumption was that once the war was over, Davis would become the newly appointed emperor.
But Davis knew that being buried in the day to day politics of running  and rebuilding the empire would make it impossible to focus resources on the Dreamhaven project.  Also, he needed support from various political factions to do the Dreamhaven project.  So a political deal was made.  He supported a moderate noble for emperor, in exchange for his support of the Dreamhaven project.  
Now they have a unique, sometimes testing relationship.  The emperor is concerned with two main objectives, in sometimes changing order.  First, rebuilding a strong and stable empire, second, insuring his power and status in said empire.
He and Davis have a relationship of convenience.  With each others support they can get much more done, and have stronger bases on power, but Davis's progressive goals are sometimes a strain for the more moderate emperor to support, especially when needing the backing and support of the more conservative constiuencies of the kingdom.  At the same time, Davis struggles with the emperors lack of interest in anything but returning to the status quo.
One way to resolve this is an agreement to support each other while staying as much as possible out of each others way.  The emporer allows Davis free reign in DH, and Davis stays at DH, safely away from domestic issues.  This is the theory at least; in practice however, the very dynamic political situation inevitably brings challenges they must work through. 
Fundamentally there is a certain basic respect between them, and even a certain level of trust, that neither is an enemy, but rather a strained ally.
Role:  Human leader; political foil
Story Activities:  While Davis is trying to develop a new, stable, diverse province as a center of international relations, the emperor is trying to rebuild a torn empire, struggling with the challenging politics of constituents from progressive to conservative.  Their interactions will come as allies and sometimes opponents, as the needs and challenges of both agendas conflict.
Character Type: Complex
Motivation:  Avoidance; Temptation
Purpose:  Perception; Inequity; Projection