This chainmail is dull and rusted, and has red links of an unknown metal woven throughout it in no discernable pattern. No amount of scrubbing and polishing can clean off the rust that has accumulated.
While wearing this armor when your speed is reduced to 0 a large dark sigil appears beneath your feet and rusty chains fly up from the ground, encircling you and any creature that grapples you or is currently grappling you. While these chains are wrapped around you you have resistance to all Bludgeoning, Piercing, and Slashing damage. Any hostile creature that is trapped by these chains or ends their turn within 5 feet of these chains takes 1d12 Necrotic damage.
Any creature entangled by the chains must make a DC 16 Strength check to escape. These chains return to the ground and the sigil disappears once all creatures trapped by them have escaped or died. The chains also release their targets and return into the ground if exposed to
Curse. Each time you fail to escape from the chains you take 1d4 Necrotic damage. If you are reduced to 0 hp while trapped in the chains they persist for 3 rounds. If you are not stabilized by the end of this time you are dragged through the ground and transported to The Abyss.