Magma Mantle
Wondrous item, rare (requires attunement)
This cracked black leather cloak is warm to the touch and faint ruddy light glows through the cracks. While wearing this cloak, you have resistance to cold damage. By touching the brass clasp and speaking the command word, you can transform the cloak into a flowing mantle of lava for 1 minute. During this time, you are unharmed by the intense heat, but any hostile creature within 5 feet of you that touches you or strikes you with a melee attack takes 3d6 fire damage. Additionally, for the duration you suffer no damage from contact with lava, and you can burrow through lava at half your walking speed.