Order of the Raging Inferno

The Blood Hunter subclass gives you access to a more in-depth use of flames and also allows you to break past those who may be able to defend against it. 

Master of Flames

Starting at Level 3, when you attack an enemy with your Rite of Flames you may choose one creature within 5ft of the target, (excluding you) that creature also takes the Hemocraft die of damage dealt by your rite. In addition, you can use your reaction to reduce incoming fire damage by your hemo craft die + your Blood Hunter level.

Starting at level 11 you can select a 2nd target, and either can be within 15ft of the original target.

Blood of Fire

Starting at level 7, when a creature damages you with a melee attack they take fire damage equal to your hemocraft modifier.

Artisan of Flames

Starting at level 11, your brand travels like a wildfire in a forest, ravaging any who dare to stand close. When you Brand a creature, creatures of your choice within 10ft of the branded creature must make a WIS saving throw or be forced to use their reaction to run their full movement away from the branded creature.

Flame Tyrant

Starting at level 15, you gain a new Blood Curse, Curse of the Flame Emperor. As a Bonus Action a creature within 30ft of you must make a CON saving throw against your hemo craft save, on a failure the target loses its resistance to a damage type of your choice, or becomes resistant if its immune, in addition you gain resistance to that damage type until the end of your next turn, on a success the creature keeps their resistance to that damage type, but you gain resistance to the damage type until the end of your next turn.
Amplified: The effect lasts for the next minute, and the creature may repeat the save on the end of their turn

Storm of Flames

Starting at level 18 you can start a raging inferno centered around you. As an action you can create a 20ft radius centered on you, and for the next minute creatures of your choice in that area have to make a CON save at the start of their then or when they enter for the first time, on a failed save they take 3d10 fire damage and have their movement halved, and take half damage and their movement is not halved. Any flammable objects not being carried or worn are ignited. This feature can be used once per long rest