Infernal Bloodline

Replaces mentions of Draconic Influence and ancestry to one of Devils. Minor tweaks to abilities to fit, no choice of damage type at level 1, and a different choice of resistance at level 6 to both fit fiendish resistances and to not overlap with Tieflings innate fire resistance.

Devil Ancestor

At 1st level you gain the ability speak, read, and write Infernal. Additionally, whenever you make a Charisma check when interacting with devils, your proficiency bonus is doubled if it applies to the check.

Fiendish Resilience

The infernal blood in your veins hardens your body. At 1st level, your hit point maximum increases by 1 and increases by 1 again whenever you gain a level in this class.

Additionally, when you aren’t wearing armor, your AC equals 13 + your Dexterity modifier.

Infernal Influence

Starting at 6th level, when you cast a spell that deals fire damage, you can add your Charisma modifier to one damage roll of that spell.

Additionally, you can use an action to spend 1 sorcery point and gain resistance to poison and cold damage, as well as advantage on saving throws against being poisoned for 1 hour.

Devil's Wings

At 14th level, you gain the ability to sprout a pair of infernal wings from your back, gaining a flying speed equal to your current speed. You can create these wings as a bonus action on your turn. They last until you dismiss them as a bonus action on your turn.

You can’t manifest your wings while wearing armor unless the armor is made to accommodate them, and clothing not made to accommodate your wings might be destroyed when you manifest them.

Authority of the Nine Hells

Beginning at 18th level, you can channel the dread presence of your devil ancestor, causing those around you to become enthralled or frightened. As an action, you can spend 5 sorcery points to draw on this power and exude an aura of awe or fear (your choice) to a distance of 60 feet. For 1 minute or until you lose your concentration (as if you were casting a concentration spell), each hostile creature that starts its turn in this aura must succeed on a Wisdom saving throw or be charmed (if you chose awe) or frightened (if you chose fear) until the aura ends. A creature that succeeds on this saving throw is immune to your aura for 24 hours.