Eoleo

Eoleo (レオレオ Leoleo) is the son of Briggs and Chaucha from Champa. On several occasions he is seen using Psynergy which leads the player to believe he is an Adept. It is assumed that Eoleo used his Psynergy power to free Briggs from the Alhafra prison which allowed Briggs and his crew to escape to steal the ship.

It is revealed through Chaucha that Eoleo obtained his powers when he was struck by a falling Psynergy Stone, in much the same way as Feizhi and Tret gained their respective abilities in Golden Sun.

Element
As his grandmother is the last resident of Champa who is directly descended from the Ankohl (who built the ruins to the north), it is possible that Eoleo's power are derived from this source as well. Considering the themes of the puzzles in the Ankohl Ruins, which heavily utilised the Sand Psynergy, this would make him a Venus Adept. Obviously, this is highly speculative, as the Ankohl is also associated with the Mercury-based Trident, and the Ankohl's forge gave rise to the Mars-aligned Avimander. Thus Eoleo's true element is unknown.

Quotes

 * On the sailing ship in Alhafra:
 * Eoleo: Goo goo ga ga! (Eoleo uses his Psynergy to make a vase float in midair)
 * Chaucha: Eoleo's only just recently started doing that... After that gem fell from the sky and hit him. He was overcome by a terrible fever, and when he recovered, he had this power.