Rust Plague

the Rust Plague is a curse laid upon the Iron Dragonflight by Sera Dagon that causes the scales of an iron dragon to rust irreversibly on contact with saltwater.

Symptoms

In cases of mere momentary contact with saltwater, the scales simply develop a subtle reddish-brown sheen. Prolonged or repeated contact causes the iron contained in the scales to oxidize and warp in shape, often fusing with neighboring scales. In some exreme cases, this fusing of scales has rendered some victims entirely immobile, as is the case with Kritü himself and his inner circle, caused by the act of flooding his lair with saltwater by the Blue Dragonflight and Aquantis Dominion hydrocasters.