While stated that all 12 Olympian Gods each possessed a respective Kamui, only one has seemingly been shown in battle on several occasions: Athena's Cloth. Having chosen to reincarnate on Earth to live as human, Athena became the planet's guardian deity against the wrath and desires of her fellow gods. Athena's Cloth was a vital element in her defense against the gods and was especially prominent in her multiple battles against the God of the Underworld Hades, where it was said it could completely turn the tides of battle, to the point where in their last two wars, Hades made several attempts to prevent the Cloth from being used against him.
As seen from a piece of concept art by Masami Kuramada of Zeus's silhouette, he also uses a Kamui.
Although members of the Olympian Pantheon and probably its ruling Council, Poseidon's reincarnation and Hades have not been seen wearing their own Kamui, wearing instead a Scale and Surplice, respectively. It is possible that each god has their own version of 'God _____' in some form, such as 'Poseidon's God Scales' or 'Hades' God Surplice' and that they all qualify in the same class comparitave to Athena's "Cloth". It is unknown if the rogue Olympian Ares has a Kamui, and in the TenKaiHen Josou Overture Movie, Apollo and Artemis are not seen wearing their Kamui.
While very little is known of the Kamui, they are by far the most powerful armors of the Saint Seiya mythos. The only known example, Athena's Cloth, which allows her to use her divine Cosmo to its full potential, was able to sustain near-endless amounts of damage from a major deity such as Hades without any visible damage to itself, and is overall the most powerful Cloth in the series, with only the full-power impact from Abzu, the creator of Universe, is able to deal extensive damage to the Kamui. These Cloths also have a much bulkier, elaborate, and ornate design, almost completely covering their user's body as opposed to the lesser armor types such the Gold, Silver or Bronze Cloths as well as most Surplices and Scales.
Athena's Cloth when not in use for large periods of time enters in state similar to that of hibernation, where it becomes the signature Athena's statue ever present at the top of the Sanctuary. However, it can be restored to its original form and power by spilling Athena's blood onto it. It's unknown if other God Cloths possess such requirements or if they possess any unique special abilities, however a statue of Hades is seen atop the pillar of the Temple of Hades at the Elysium fields, although the possibility of it having any relation to Hades's Kamui has never been confirmed.
The Divine Cloth was stated by Hypnos to be one type of mortal-made Cloth that was closest to the power and prominence of a God Cloth.