The distinction the series keeps returning to — the difference between what started the Assassin and what sustains them. Revenge is Ezio's fuel in the early game: the executions, the family, the specific grief of having stood in the piazza and watched. Purpose is what he is building toward: the understanding that the Pazzi are not the disease but a symptom, that the Templars are the structure that produces the symptoms, that the aim of the blade needs to extend beyond the immediate targets.