Gigas was the commandant of the army of Athena, during the rule of Saga in the Sanctuary. He controls who is sending, for the pope who does not worry about this every time. Piton was his assistant and have the power to send servants of Athena too.
Gigas, because his office, sent various servants of Athena to kill recover the Sagittarius cloth helmet. He has sent Docrates initially, and after, Piton sends the Caraib Ghost Saints to bring the helmet, promising to Gigas the victory, but fails. So, Gigas forces the peoples of the Kohoutek Village's to build an Ice Pyramide.
As a last attempt, sends the Ennetsu Saint (an orphan who is under the tutelage) to recover the helmet (and goes together his loved adopted son, and tries to steal the helmet directly from Saori in her house), but with his foes, Gigas get away and fades away, because the pope will not accept a new foal.