Flynn is a childhood friend of Yuri's, as well as a friend to Estelle. He joined the Imperial Knights at the same time as Yuri when they were younger for the purpose of "making a difference" in the world. But unlike Yuri, he stuck with it and has since continued to climb higher in rank, becoming the youngest to receive the title of Captain. He often helps the party deal with problems in their travels. He has a sense of justice similar to Yuri's, but he pursues it through a different method, attempting to solve matters through peaceful politics rather than forceful rebellion. He is unplayable in the Xbox 360 version of the game, but is a playable character in the Japanese PS3 version.
Source from Wikipeida