After failing to attune to a powerful elemental artifact of the Cinder Plane your body was catastrophically damaged. When you were revived you realised your arm had been altered from the extra planar energy, now being a blackened volcanic rock.

• Your volcanic arm deals 1d6 fire damage to any creature it touches, including with unarmed attacks, and ignites any flammable substances it touches.
• Your arm is permanently glowing with bursts of cinders. You emit a dim light for 5 feet and have disadvantage on stealth checks.