When traveling to Earth in Phantasy Star Online 2, ARKS came across a new breed of enemy they dubbed Phantoms. They are ethereal, almost ghost-like opponents who seem to draw from people's fears. They are under the command of the Mother Cluster, behaving almost like Darkers in more ways than one. A fine mix of both organic and vehicular Phantoms exist across Tokyo and Las Vegas, and they are all capable of generating extra appendages for their attacks.
Las Vegas Phantoms
Upon entering Las Vegas, ARKS were created by a number of more extravagant Phantoms, now drawing from movies and other American inspirations. They are all weak to Wind, while Vegas Illusia is also weak to Bolt.
The Mother Cluster is a group of characters who serve under Mother; this includes Aratron, Ophiel, Och, Phul, Bethor, Phaleg, and temporarily Kohri. They are known to have control over the Phantoms, but it is revealed that they aren't inherently evil later on in the story. Despite that, there are a few times where ARKS must confront them in battle before learning the truth. Their weaknesses vary, but the Phantoms associated with them are typically weak to Wind.
After obtaining the powers of a Dark Falz from Aru, Mother was able to conjure her own type of Darker. They are still considered Phantoms, and have taken on a blue appearance as opposed to the usual black coloring. They are recolors based on all four types of Darker, and are all weak to Wind and Light.
Upon defeating Mother, ARKS are then betrayed by Ardem who then uses Mother's power to force humanity to evolve; in doing so, he turned many members of the Earth Guides into Angels, a new enemy type which are still considered Phantoms. They are all weak to Dark, though all forms of Deus ESC-A are weak to Light as well.
Thunder Bear and Mint Bear are special enemies featured during a single Limited Quest each. Thunder Bear, based on Brown Bear, is weak to Wind and Bolt; Mint Bear, based on Polar Bear, is weak to Wind and Dark.