The exclusive #500th Pokemon made for Pokemon: Jesus Editon. You have to accept Jesus as your savior to unlock Tristan, who is located in Jerusalem. You can only catch Tristan with a Jew Ball, which is recieved when you defeat the Muslim Infidels, earlier in the crusade. Tristan is level 95, making him the strongest Pope in the game.
"Yeah, I tried catching Tristan with my Charzard. Fucking Pope spilled holy water on it KO'ing it."