Credit: Kyounghwan Kim

Pact Boon:

Pact of the Gauntlet

Your patron grants you a gauntlet crafted of unearthly black iron. While you wear the gauntlet, you gain AC equal to 16 plus your proficiency bonus, but you gain no further AC from armor nor from Dexterity, and you have disadvantage on Dexterity (Stealth) checks because of the otherworldly magical aura it emanates. The gauntlet's aura and appearance may also have an effect on Charisma (Persuasion) and Charisma (Intimidation) checks at the DM's discretion. A one-hour special ritual is required to don or remove the gauntlet.

New or Modified

Eldritch Invocations

Black Iron Endurance

Prerequisite: Pact of the Gauntlet feature

All of your hit dice from Warlock levels are d12's. (Your hit points per level are unaffected.)

Black Iron Aegis

Prerequisite: 5th level, Pact of the Gauntlet feature

When an ally within 30' of you takes damage, you may use your reaction to expend hit dice without healing, and negate an amount of that damage equal to the healing you would have received. The most hit dice you can expend at once in this manner is equal to the number of warlock spell slots for your level.

Soul of Iron

Prerequisite: 12th level, Pact of the Gauntlet feature

You may expend a warlock spell slot to regain recovery dice equal to half your warlock level, rounded down. This requires 5 minutes of ritual meditation. You can't do this again until you finish a long rest.

Fiendish Vigor

You can cast false life on yourself at will as a 1st-level spell, without expending a spell slot or material components. Additionally, Gauntlet Pact warlocks may do this once as a bonus action, and recover this additional ability after a short rest.