Atlanticans are a humanoid race which has lived in the Mortal Dimension for years now, undetected, because of their advanced technologies. Like the humans and sages, their appearance is much like that of the Perfect. The Atlanticans harness particles released from dimensional energy and, much like the two cores, recycle those particles into usable dimensional energy. Only, unlike the cores, they use that energy for their own gain, not for the dimensions. They can use this converted dimensional energy to manipulate existence around it, to a limited degree, depending on their skill level.
This process is known as Ocean. Ocean works through an Atlantican's physical contact with a dimension. By being within a dimension, they are basically "charging their batteries", if you will. An Atlantican is basically the polar opposite of a Warrior, or avatar of one of the cores, such as Jay. Whereas the warriors have absorbed vast amounts of dimensional energy and use that energy, the Atlanticans absorb excess dimensional particles and recycle the particles. Their bodies contain various pores which act like Databusses, absorbing the energy and bringing it into the body where it is recycled.