Aguro is the stereotypical strong man of your party. He can do a crazy amount of damage when properly equiped, but can use absolutely no magic. This fault is rarely apparent, however, since you never have Aguro in your party without a magic user that can at least heal, be it Lufia, Hero or Jerin. You only have to worry about the lack of magic should Aguro be the only member of your party left alive, but then you can use a revive on another member (you did buy lotsa revives and miracles, didn't you?)
You find Aguro in the port of Treck after fighting Gades. You find Aguro in the port of Treck after you see Guy, one of the two survivors of Maxim's party. Aguro is a member of the Lorbenian army, and came in his ship, the Maberia, to investiate Gades' ttack on Sheran. You confront him to ask for use to his ship, but are attacked by a difficult group of enemies. After you beat them, the ship has been stolen and you must locate it. After killing the even more difficult trio of Goblins that stole the ship, Aguro becomes a permanent member of your party.