Path of the Volcano

A barbarian who has chosen The Path of the Volcano harness their anger and turn it into searing heat. Their hearts burn with literal heat and explode in vicious tempests of fiery force. 

These barbarians might find a djinn or similar being in their heritage or have spent a significant amount of time around actual sources of lava and magma.

Searing Presence

Starting at 3rd level, searing heat bursts out of your body while you rage. The heat bursts out in a 20 ft radius from you in every direction, but not through total cover.

When you enter your rage, every creature within its area of effect must make a Constitution saving throw; the DC equals 8 + your proficiency bonus + your Constitution modifier and are stunned on a failed save and take 3 fire damage each regardless.

The damage increases when you reach certain levels in this class, increasing to 5 at 5th level, 7 at 10th level, 9 at 15th level, and 11 at 20th level.

Retardant Skin

You gain resistance to fire damage, and you don’t suffer the effects of extreme heat, as described in the Dungeon Master’s Guide. Moreover, when you begin your rage, you gain immunity to fire damage for 1 minute.

Thermal Stomp

At 10th level, you learn to use your inner heat and physical might to produce a local quake. As an Action, you stomp the ground and attempt to knock any creatures of your choice prone in a 30 ft radius centered around yourself. Creatures affected by your stomp must make a Strength (Athletics) or Dexterity (Acrobatics) check (the target chooses the ability to use). The DC equals 6 + your proficiency bonus + your Strength modifier.

You can take this action a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.

The range increases to 60 ft. at 14th level

Magmatic Warrior

At 14th level, your blood has become like liquid rock. Whenever you take slashing or piercing damage, your blood spews out in a 10 ft cone towards your attacker, dealing 5d8 fire damage on a hit.