This horned mask of glossy ebony has horns and a skull-like mien. The mask reshapes to fit a wearer attuned to it. While you are wearing the mask and attuned to it, you can access the following properties.
You have resistance to acid damage. If you already have damage resistance to acid from another source, you gain immunity to acid damage. If you already have immunity to acid damage from another source, you regain hit points equal to half of any acid damage you are dealt.
While you are wearing no armor, you can add your Charisma bonus to your Armor Class.
If you have a breath weapon that requires rest to recharge, it gains a recharge of 6.
You gain darkvision with a radius of 60 feet, or an additional 60 feet of darkvision if you already have that sense. Once per day, you can gain blindsight out to a range of 30 feet for 5 minutes.
You can speak and understand Draconic. You also have advantage on any Charisma check you make against Black dragons.
(1/Day) If you fail a saving throw, you can choose to succeed instead.
You can breathe underwater.