Just my 2 cents, but I would caution against multiple GMs unless we truly need them due to group size and game scope. You invite in multiple possible issues when you have multiGMs. 

[quote=21308]My first thought was of am Alistair who survived by learning to use the darkspawn disease inside him to control them.[/quote]

That's kinda silly. If the Horde isn't defeated than there is still an archdemon. Hey Horde this is Alistair, you know that kinda dopey Grey Warden who failed to defeat you, yeah I know your minds are bent under the control of an Ancient Corrupted God-Entity, but if you could follow my instructions instead that would be just swell. 

Even the Architect and the Mother, those awakened darkspawn demi-gods from the sequel, could not gain influence until the Archdemon had fallen.