Dark

The concept of Dark is first officially introduced near the end of Golden Sun: Dark Dawn. Very little is known about it, except that Dark Psynergy does exist somewhere in Weyard (whether or not it is a proper element is still debatable). The following is what has been confirmed about Darkness:

Dark, like Light, was discovered as a result of the ancient inhabitants of Weyard's endless search for more power. Having mastered the four known elements, they sought further control over alchemy, a quest Kraden would describe as a search for nothing short of omnipotence. To this end, they built the Eclipse Tower, a device which absorbed light. An unexpected side-effect is that a huge area of Darkness was created across Weyard, known as the Grave Eclipse. Eclipse Tower was later sealed and deactivated, until the events of Dark Dawn.

Dark-aligned abilities are not common knowledge to Weyard's present-day inhabitants, leaving Darkness shrouded in mystery. What is known is that Dark is diametrically opposed to heat and light, as evidenced by the adverse reaction to fire that the trees of the Tanglewood exhibited. Further, Dark gives rise to powerful monsters, such as the Tangle Bloom and the monsters encountered during the Grave Eclipse. The Chaos Hound encountered at the end of Dark Dawn is a monster created by infusing a living being with Darkness. These monsters dislike strong light sources, as evidenced by Obaba keeping Champa free from the Grave Eclipse monsters by maintaining a massive bonfire.

Although no "Dark" element has been programmed into the game, Blados has confirmed that there are Adepts with Dark Psynergy. The only known Dark Psynergy users are the Umbra Clan and, by extension, Tuaparang. The monster skill "Shadow Shield", used by both Blados and Chalis, may be a Dark-aligned skill, although this has not been confirmed.

Psynergy Vortexes, thought not confirmed to be Dark, act in much the same manner as the Grave Eclipse, although they absorb Psynergy from the environment rather than light. Also worth mentioning are the Psy Grenades wielded by Tuaparang's soldiers, which, like Psynergy Vortexes, drain Psynergy.

The Umbra Gear is a set of equipment that may be Dark-aligned, as they absorb light (and possibly Psynergy, as evidenced by each item giving the wearer a Resistance boost), making passage through the intense light of Apollo Sanctum possible.