The Dark Guardian is a much larger and monstrous version of the regular Nightmare Dark Gaia Creatures, resembling a humanoid lizard with four fingers, a large head and a thin tail. Colored in a light-purple, its eyes are colored white, with a sky blue jagged horn turned over the right side of its face, and it has long and spiky sky blue hair on its head. It also has lightning-shaped motifs around its eyes, which are also colored sky blue. As attire, it has gauntlets surrounding its arms and legs and a golden ring around its right wrist.
Shattered World Crisis
During the Shattered World Crisis, the Dark Guardian was created from the dark energy released across Sonic's World by Dark Gaia when it awoke from its slumber. Raised from the Anostos Rift, the Dark Guardian and its kind harassed the underwater city of Meropis and its civilians. When the city lost its protective shields due to its sustainer Coral the Betta giving in to emotional stress, the Dark Guardian and hordes of Dark Gaia Creatures swarmed the city. There, the Dark Guardian ambushed Sonic the Hedgehog and Rotor the Walrus, who were helping the Meropis City Guard with the Dark Gaia Monsters. While they fought however, the two Freedom Fighters began to run out of air when their Air Charms gave out, but the Dark Guardian kept them below the sea.
The Dark Guardian almost succeeded in drowning the two Freedom Fighters, but then Chaos arrived and gave Sonic and Rotor air bubbles, allowing them to breathe. The Dark Guardian then began fighting Chaos, but found itself at a disadvantage as the living wave used the entire ocean against it, and Sonic, Rotor, and Captain Striker the Mantis Shrimp soon after joined the fray. Shortly after, with the help of a combined Mystic Melody from Coral, Pearly the Manta Ray, and Tikal, the Dark Guardian was weakened, allowing Sonic and Rotor to destroy it.
Powers and abilities
A formidable foe, the Dark Guardian is very powerful. It had impressive durability for its kind, withstanding the combined assaults from the world-renowned hero Sonic the Hedgehog and Rotor the Walrus. It also possessed high physical strength as it could throw its opponents very easily without any struggle, even in underwater.
Like other Dark Gaia Creatures, the Dark Guardian is seemingly capable of aquatic respiration, allowing it to reside underwater without any need of oxygen.
The Dark Guardian wields a massive mallet with a large head that it uses as a standard melee weapon.