The Dark Spirals are more powerful versions of the Dark Rings, created by the Digimon Emperor, which run on their own independent power source and do not need the Control Spires to power them. After his experience with SkullGreymon, the Emperor realised that Dark Rings were not powerful enough to control Ultimate level Digimon, and so created the Dark Spirals for that purpose. Agumon, held captive by the Emperor, had a Spiral attached to him, and was then Dark Digivolved into a viral version of MetalGreymon by the Emperor's D-3. This Spiral was destroyed by Raidramon, and so the Emperor developed a more powerful version, which was then seen to be used on Gorillamon, Digitamamon, Ninjamon, ShogunGekomon, MegaSeadramon and Dokugumon. The "Scubamon" in theWorld of Darkness were seen to have Dark Spirals attached to them, but apparently they were not real, and were merely used to dupeKari into helping them so they could capture her. Dark Spirals first appear in "The Captive Digimon."