Dekn from Universe X are actually evolved Humans from the Origin Seed. This was a seed that is said to have housed a humanity tampered with by Cedric, and later released into two respective realms where evolution into a new wave of Universe A Arkn and Dekn was forced. After humans from this seed had been moved out into the Lathrym, the Seed was duplicated into the Five Seeds of Ersis. Dekn powers link directly into the Sil'ulis, allowing what they manipulate mentally in that plain, to manipulate physically in the Lathrym or Ersis. They received this power from forced evolution, courtesy of Cedric.