Darkness 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 Light, 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 Darkness as a form of Psynergy like a normal element is revealed late in Dark Dawn.
Blados and Chalis, along with various other soldiers from the Tuaparang Empire, belong to what calls itself the "Umbra Clan", supposedly named in the same style as the other Elemental Clans familiar on Weyard but having never been heard of by anyone before. They call themselves Dark Adepts because they supposedly have the ability to use Darkness as Psynergy (however, no "Dark Element" exists in the actual game's gameplay; even though the Psynergy that Blados and Chalis use visually appear dark, they are aligned with normal elements).
Role in story
Dark-aligned abilities are not common knowledge to Weyard's present-day inhabitants, but were discovered in the ancient past. Having mastered the four known elements, the world's ancient inhabitants sought further control over alchemy, a quest Kraden would later 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.
During the Grave Eclipse, many powerful "dark" monsters appear. These dark monsters are stronger than normal monsters, but have an aversion to strong light sources. This weakness protected cities like Harapa from the Grave Eclipse, and Obaba was able to keep Champa free from the dark monsters by maintaining a massive bonfire. Also worth mentioning is the Chaos Hound encountered at the end of Dark Dawn, an otherwise-normal being forcibly infused with darkness.
Thus far, the only obvious feature of Darkness is its association with monsters, with stronger monsters being more strongly tied to darkness. With this in mind, it is worth noting that both known dark adepts had features that weren't human nor did they resemble animals like the beastmen of Morgal.
Phenomena similar to darkness
Although central to Dark Dawn, the concept of Darkness is poorly defined at best. What follows is a list of phenomena similar to darkness, although whether or not they are actually related remains in the realm of speculation.
- The Tanglewood, Dark Dawn's tutorial-esque dungeon, is a normal forest by day but transforms at night, with large roots growing out of the ground to trap anyone unfortunate enough to wander in. These roots were eliminated by burning certain flowers with the Fireball Psynergy, similar to how strong fires can keep Grave Eclipse monsters at bay.
- Psynergy Vortices act in much the same manner as the Eclipse Tower, 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 elemental Resistance boost), making passage through the intense light of Apollo Sanctum possible.