3. The Hunnic Empire
At the minute, the franchise is established on a narrative foundation of the Assassins against the Templars, but there is nothing to say that in future - with 10 Assassin's Creed titles having been mentioned as an ideal - Ubisoft won't change protagonists entirely. If and when they do that, an Eastern setting pitting the Huns under Attila against their European enemies in the various Hunnic campaigns would be a setting worthy of the Assassin's Creed name. The protagonist could either be a Hun himself, invading different Western countries like Constantinople and Venice or a member of the repelling force, reclaiming invaded territory and taking out Hunnic leaders. The mystery surrounding Attila's death - and the various accounts of its cause - would leave ample space to create a narrative solution incorporating the Assassins that would offer a good opportunity for a finale to the game or game series.