Path of Hellfire

Through either making a pact with a devil, or embracing their own infernal nature, Barbarians who have chosen to walk the Path of Hellfire fuel their rages with the fires of the Nine Hells. Marked by a darker power, these ferocious warriors channel the rage from the deepest pits of the Nine Hells to scorch their enemies to darkened crispy husks of their former selves.

Hellfire Barbarians use their ability to bend hellfire to their will to bolster their endurance, strike with burning fury, or take on scores of enemies with the fires of the Nine Hells. The most powerful are able to even use their flames to pierce through even the mightiest creatures of the pit. 

Infernal Legacy

Starting at 3rd level, your connection to the Nine Hells grants you gain resistance to fire damage. Additionally, while raging, you have advantage on saving throws against being charmed.

Hellfire Strike

At 3rd level, you unleash the fires of Hell with your attacks. On one of your attacks per turn while you're raging, you fuel your strikes with a burst of hellfire when you hit a target with a melee weapon attack. When you do, that target takes an extra 1d6 fire damage from the attack. This damage increases when you reach certain levels in this class, increasing to 2d6 fire damage at 10th level and 3d6 at 14th level. 

Relentless Inferno

Your rage burns with the relentless fury of the Nine Hells. When your rage would end early due to you either not attacking or taking damage, you can choose to maintain it instead. You can use this feature once per round, a number of times equal to your Constitution modifier (minimum of 1). You regain all expended uses when you finish a long rest.

Hellish Influence - Fiendish Charm

Beginning at 6th level, you embrace the fiendish legacy of influence and deceit.

As an action, you can magically charm one humanoid you can see within 30 ft. The target must succeed on a Charisma saving throw, the DC equals 8 + your proficiency bonus + your Charisma modifier. If they fail the saving throw they are magically charmed for 1 hour, and obey your spoken commands. If the target suffers any harm from any creature, the target can repeat the saving throw, ending the effect on itself on a success. If a target's saving throw is successful, or if the effect ends for it, the creature is immune to the Fiendish Charm for the next 24 hours.

Once you use this feature, you can’t use it again until you finish a long rest.

Hellish Influence - Bonus Proficiency

Beginning at 6th level, you embrace the fiendish influence of lies and manipulation. You gain proficiency with the Deception and Persuasion skills.

Devouring Inferno

Beginning at 10th level, while you are raging, you draw upon the fires of the Nine Hells to start generating a blast of hellfire. As a bonus action on your first turn, you begin generating an inferno centred on yourself, the radius being 5ft multiplied by your proficiency bonus. The inferno fades if you move or are moved while generating it, or until you lose your concentration (as if you were concentrating on a spell). 

At the start of your next turn, you release the inferno, and each creature within the radius must succeed a Dexterity saving throw, the DC equals 8 + your proficiency bonus + your Constitution modifier. On a failure, they take 6d6 fire damage, and are knocked prone. On a success they take half of the damage and are not knocked prone. Your rage then ends. 

You can use this feature a number of times equal to your proficiency bonus. You recover all expended uses after a long rest. 

Searing Fires of Phlegethos

Starting at 14th level, the power of your infernal communion connects to your soul, causing your flames to become too intense for even the mightiest of the Nine Hells. Fire damage you deal ignores resistance and immunity. Additionally, you gain immunity to fire damage.