Helldusk set

Helldusk armour is a set of equipment that revolves around resisting and dealing Fire damage. It is forged from Infernal Iron.

Flawed

The Flawed variants of the Helldusk set can be produced by Dammon, who apprenticed under Carixim, if he is given Infernal Iron.

Name	Slot	Effect
Flawed Helldusk Armour	Armour (Heavy Armour)	Lesser Infernal Retribution When you are hit by a foe within 2 m / 7 ft, it might take 1d4Fire damage. Superior Plate You take 1 less Piercing damage.
Flawed Helldusk Helmet	Headgear (Non-Armour)	Magical Durability The wielder has a +2 bonus to Saving throws against spells. Constitution Saving throws +1
Flawed Helldusk Gloves	Gloves (Non-Armour)	Strength Saving throws +1

Non-flawed

The non-flawed (or perfect) variants of the Helldusk set are originals produced by Carixim. They have more powerful effects but are harder to acquire. It seems that the order in which Dammon gives the party the pieces is: First the Flawed Helldusk Armour, then the Flawed Helldusk Helmet, and then the Flawed Helldusk Gloves.

Name	Slot	Effect
Helldusk Armour	Armour (Heavy Armour)	Fly () Cast as a level 3 spell ( Recharge: Long rest.) Helldusk Armour You are considered Proficient with this armour while wearing it. Infernal Retribution When you succeed a Saving throw, the caster receives  Burning for 3 turns. Prime Aegis of Fire You have Resistance to Fire damage and cannot be  Burned. You take 3 less damage from all sources.
Helldusk Boots	Footwear (Non-Armour)	Hellcrawler () Teleport to an area and deal 2d8Fire damage where you land. The impact blast spreads in a 3m / 10ft zone. ( Recharge: Short rest.) Steadfast You cannot be forcibly moved by a foe's spells or actions, and you ignore the effects of  Difficult Terrain. Infernal Evasion When you fail a Saving throw, you may use your Reaction to succeed instead.
Helldusk Gloves	Gloves (Non-Armour)	Strength Saving throws +1 Rays of Fire () Cast as a cantrip ( Recharge: Short rest.) Infernal Acuity You gain +1 bonus to Spell Attack Rolls[See Notes] and Spell Save DC. Infernal Touch Your weapon attacks deal an additional 1d6Fire damage. Your unarmed attacks deal an additional 1d6Necrotic damage, and can possibly inflict  Bleeding.
Helldusk Helmet	Headgear (Non-Armour)	Attackers can't land Critical Hits on the wearer. Immolating Gaze () Sear and  Frighten a target with nothing but your glower. ( Recharge: Short rest.) Infernal Sight You can see in magical and ordinary darkness up to a range of 12 m / 40 ft. You cannot be  Blinded. Magical Durability The wielder has a +2 bonus to Saving throws against spells.