Light

Light is introduced in Golden Sun: Dark Dawn as one of the two yin-and-yang-like values that help bring existence into being, along with Darkness, separate from the four great Elements that comprise all physical matter - Venus, Mars, Jupiter, and Mercury. It is not certain whether this qualifies as an Element in and of itself, but the concept of employing Light as a form of Psynergy like a normal element is briefly touched upon at the end of Dark Dawn.

The Apollo Lens has the ability to shoot a concentrated beam of Light energy, and when it is shot at Eclipse Tower in Belinsk, the beastman denizens of the city later report that they were endowed with the ability to project light as Psynergy when they were caught in the light. These beastmen's fur color is changed to bright yellow to reflect this, such as Vande.