Things Assassin's Creed III Could Learn From Eternal Darkness, Part One

Critically speaking, Assassin's Creed II has been widely considered to improve on its predecessor in almost every way possible. Visuals, narrative, production value, and combat system- all of the aforementioned properties have at least been tweaked(and at most, upgraded) with a financial system layered in for good measure. If this is indeed the case, how should Ubisoft approach properly concluding this trilogy? This question may have been answered by Silicon Knights in the previous console generation.