Ristoro is a minor antagonist in the video game Assassin's Creed: Brotherhood. He was a Minim priest and a member of the Templar Order.
Around 1500, Cesare Borgia began recruiting men and women that could be valuable to his cause. He soon came across Ristoro, who he became interested in. In exchange for several girls to feed his "appetite," Ristoro provided the Borgia with religious icons, amulets, and equipment. He also gave coin to pay off contacts and documents officially sealed by the church, such as letters of absolution or condemnation.
Ristoro often visited the Rosa in Fiore, the most popular brothel in Rome, without paying heed to his vows of purity. Out of all the courtesans who worked there, he particularly favored Fiora Cavazza, though she was revolted by both him and his "perversions."
Upon being recruited by Cesare Borgia, Fiora was forced to meet with Ristoro again. Though she hoped he would not recognize her, Ristoro picked her out from the crowd of girls she had been tasked to deliver to him.
Ristoro then stroked Fiora's cheek, saying that she had always been his favorite, causing her to kick him between the legs and threatened him with Cesare's wrath. Ristoro then whimpered and withdrew, but attempted to touch her again as she left, though he only stopped when he became distracted by the other girls who had been sent to him.
Ristoro's ignorance of his vows did not go unnoticed by his brothers. At one point, two of his students started questioning him about his practices. In response, Ristoro poisoned them both, though he was able to buy his absolution from the crime with the help of the Borgia.
A third brother began to speak out against him as well, announcing his misdeeds to a crowd gathered near the Colosseum. As he did so, the Assassin Ezio Auditore approached him, asking of Ristoro's acts. Upon hearing the full account, Ezio decided to seek the priest out.
Ezio located him at a church, where Ristoro was surrounded by Borgia guards and was wielding a spear for protection. However, the Assassin easily overcame the guards and assassinated Ristoro from above, using his Hidden Blade to kill the corrupt priest.