Brother Ristoro is a Templar assassin during the Renaissance in Italy. He appears both in the Single-Player and Multiplayer components of the game, though under different names. In online multiplayer, the character of Ristoro is called 'The Priest'. Ristoro is a member of the Order of the Minims, but does not follow the pure life he is intended to.
In online play, Ristoro's weapon is a Holy Dagger, despite the artwork depicting him wielding a crucifix. Ristoro is unique in this fact, as the artwork for all of the other online characters displays them wielding their weapons of choice, rather than something relating to their profession. The name 'Ristoro' is Italian for 'renovation', which is fitting with the Latin meaning of the term 'Abstergo', which is 'I cleanse'.