Armor (chainmail), Rare (Requires Attunement)
The Granite Defenders of the Dimlodir vault are gruff and sturdy dwarves that have weathered many wars. Their appearance is made even more unyielding while clad in their heavy chainmail.
Each ringlet of the chainmail is made of animated granite. At the wearer’s command, the armor can stiffen and become a veritable wall against opponents. The drawback, of course, is that the dense armor compromises mobility. For a defender of the richest vault in the Vast Kingdom, that isn’t much of a compromise as enemies more often than not come to you.
Mechanic
As an action, you can speak a command word to cause this armor to harden. Doing so causes your AC to increases by 2. While the armor is hardened, your speed is reduced by half and you have disadvantage on Dexterity saving throws. The effect lasts for 10 minutes or until you use a bonus action to dismiss it.
Additionally, once per long rest, you can cast meld into stone on yourself and step into a stone object or surface large enough to fully contain your body.