Fulien K. Lester

From Aselia, the Tales wiki

The main character of Tales of the World: Summoner's Lineage who, like his ancestor Claus F. Lester, is studying the principles of summoning. Though his knowledge on the subject still has a way to go, and his work ethic is questionable, he shows significant potential and is able to summon a large variety of creatures even at his novice state. In battle he is responsible for fortifying the player's army with additional units, and can even change his elemental alignment given the situation. He is constantly followed by his fairy-like friend Macharon, who gives him advice along the way.