Path of the Raging Fire

Your rage isn’t normal, the hatred you have inside for your enemies and the heat of combat shows in the form of a raging fire that aids you in defeating those you wish to be dealt with. You seem to have a connection with the elemental plane of fire, whether that connection could be that you're from there, your heritage or you or your parents made a deal/friend with a fire elemental and gave you a gift of its power. However you acquired this power, it’s made visible with your anger, leaving all your enemies with burn scars and full of fear (That is if you kept them alive)

Fiery Form

At 3rd level, when you’ve chosen this path, when you rage, fire sprouts out from your body and your eyes glow red as if you are now a walking cloud of flame. Your head doesn’t get covered and people can still clearly see your body through the flames. But you also gain the following benefits

• You have advantage on all Intimidation checks made while raging.
• You shed bright light for 10ft and dim light for an additional 10ft.
• While raging, you can use a bonus action to send out a small pulse of fire in a 5ft radius centered on you that deals fire damage equal to your Proficiency bonus to all creatures in the area. You can use this feature a number of times equal to your Proficiency bonus.
• While being grappled or grappling a creature, it takes fire damage equal to your Proficiency bonus at the start of its turn.
• You gain resistance to fire damage.

Additionally when you choose this subclass, your body temperature is naturally higher than that of a normal person. You gain resistance to cold climates but not cold damage

When picking this Subclass, you also obtain the Control Flames cantrip (Constitution is your spell casting ability modifier)

Ignite

Additionally at 3rd level when you choose this path, as an action you can ignite a small object to other light a torch or start a campfire as you let if elemental power within you flow into that object, causing it to ignite  

Weapons of Fire

At 6th level, you are able to control your flames from your Fiery Form to also spread it to any melee weapons you wield. Well holding any melee weapons, your flames coat the blades and any attack you make with those weapons deal an additional 1d4 fire damage, they lose this ability once they leave your hand or your rage ends. The Weapons of Fire damages is also applied to any unarmed strikes to make during your rage (The damage increases to 2d4 at level 14)

Exploding Presence

When you reach 10th level, well you’re raging, your flames get even deadlier and you can control them to expel out of you in an area to damage a group of people all at once.

• The light you admit is increased to 15ft bright light with 15ft dim light
• As an action while your raging, you can make your flames explode from your character in other a 15ft radius centered on him/her or a 5ft by 30ft line that explodes out of his/her chest. Each creature in the area must make a Dexterity saving throw against your DC (8 + your proficiency bonus + your Constitution modifier) or take 4d8 fire damage on a failed save and are pushed back 5ft from the force, or half as much on a successful save and is not pushed back. You can use this ability once per short rest

Soul Ignition

At 14th level, when you rage, you can choose to make your flames burn hotter than ever before, so hot that they actually start to burn you as you sacrifice some of your life for power. Your once orange, red and yellow flames, now turned a deep and light blue with your eyes now glowing navy blue, Leaving you with burn marks when it’s over

While it’s active, you gain the following benefits and side effects.

• When you activate Soul Ignition and at the start of each turn, you take fire damage equal to half your Barbarian level (Rounded up) and you gain a level of exhaustion once it ends
• You are resistant to cold damage
• Your flames now ignore resistance to fire damage
• You shed bright light for 30ft and dim light for an additional 30ft
• Your Exploding Presence ability does extra fire damage equal to half your Barbarian level (rounded down) + your rage bonus and now pushes enemies 10ft away
• Your Weapons of Fire damage is increased to 2d6 + half your rage bonus (Rounded up)
• Your Fiery Form pulse does double damage 

This ability works from your rage. When your rage ends in any way, this ability also ends. You can use this ability only once per long rest/day