Secondary Nature—Grey Kinesis Deity!
It was what Maroppa relied upon to temporarily unleash the effects of Sandy Grey Void without any effects on the environment. The moment she retracts the power, the region of Sandy Grey Void would recover to its original state.
Hence, once the ability had been unleashed, the grey sand that had formed within the Sandy Grey Void wasn't real. It could pretty much be stated as a mineral capable of temporarily unleashing the effects of the real grey sand.
The Influenced Region of Armoury targeted this fake grey sand, using it to create multiple Spirit Weapons, one of which had the qualities of forcefully shutting down the temporary Sandy Grey Void. That was the nail that Inala had brought out, which Resha had transformed into a sword to cut through the pillar of night that Yarsha Zahara had erected.
