Supplicants are available in Co-op Missions when playing as Alarak. They are produced in pairs, in a manner similar to zerglings. They automatically sacrifice themselves to keep Alarak alive when in close proximity to him. They can also be sacrificed to fully restore the energy of an ascendant.
While numerically superior, supplicants are very poor units offensively, dealing little damage at a short range. There is little need to producing supplicants if the player is not making heavy use of Alarak or ascendants.