Fighter Archetype:

Djinn Knight

Djinn Knights are warriors of great sorcerous power. Elemental magic flows through their veins, allowing them to improve their martial prowess with elemental abilities. Whether a loyal vassal of a powerful genie lord or simply a warrior tainted by the energies of the Elemental Planes, Djinn Knights fight with an unnatural tenacity fueled by sorcery.

Source

Starting at 3rd level, you gain a pool of energy you can draw upon known as source points. You have source points equal to 1 + your Charisma modifier (minimum 1). Once you use a source point, you cannot use it again until you finish a short or long rest.

If a source power requires a creature to make a saving throw, the DC for the saving throw is equal to 8 + your proficiency bonus + your Charisma modifier.

In addition, choose the Element of your Source: Flame, Earth, Air, or Water. This determines what damage your Elemental Smite feature does as well as which features you get as you earn more levels in this class.

Sources

Source Element Smite Damage Type Features Flame Fire Fiery Lash, Fire Tongue, Fiery Rebuke, Volcanic Lash, Heat Wave Earth Acid Earthen Body, Tera Sculpter, Resilient, Iron Body, Stone Shell Air Thunder Guiding Winds, Storm Commander, Redirecting Gust, Soaring Winds, Lightning Strike Water Cold Ice Storm, Sea Dweller, Frost Spray, Frost Nova, Cold Snap

Elemental Smite

Beginning at 3rd level, you can enhance your blows with elemental magic. Once per turn, whenever you hit with a weapon attack, you can spend source points to increase your damage. This bonus damage is equal to 1d6 per source point spent, to a maximum of 3d6, of a damage type correlating to your Source element.

Source Power

At 3rd level, you gain the Source Power below that correlates with your chosen Source.

Flame - Fiery Lash

As a bonus action, you can spend 1 source point to attack an enemy within 15 ft of you with a fiery lash. Make an attack using Charisma as your attack modifier, adding your proficiency bonus as normal. On a hit, that creature takes 1d8 + your Charisma modifier fire damage. You can use Elemental Smite with this ability, but not if you've already used Elemental Smite this turn.

Air - Guiding Winds

As a bonus action, you can spend 1 source point to summon mystical winds that push and guide you. Until the end of your turn, your walking speed increases by 10 feet and your movement does not provoke opportunity attacks.

Water - Ice Storm

As a bonus action, you can spend 1 source point to cause a fierce ice storm to surround you. Each creature in a 5 foot radius of you takes 3 cold damage and the radius becomes difficult terrain until the start of your next turn.

Earth - Earthen Body

As a bonus action, you can spend 1 source point in order to have bony, rocky plates cover your body. You gain temporary hit points equal to your Charisma modifier + half your fighter level. These temporary hit points last for 10 minutes.

Command of the Elements

Beginning at 7th level, you gain one of the following features correlating with your chosen Source.

Flame - Fire Tongue

You gain the Control Flames and Light cantrips. Charisma is your spellcasting modifier for these spells. In addition, you don't suffer the ill effects of traveling in extremely hot environments.

Air - Storm Commander

As a bonus action, you can change the direction of wind within a 100-foot-sphere of you and either increase or decrease the speed of the wind by 5 miles per hour. In addition, your walking speed increases by 5 feet.

Water - Sea Dweller

You gain the ability to breathe underwater and you gain a swim speed equal to your walking speed. Any increases to your walking speed also apply to your swim speed. In addition, you don't suffer the ill effects of traveling in extremely cold environments.

Earth - Tera Sculpter

You gain the Mending and Mold Earth cantrips. Charisma is your spellcasting modifier for these spells. In addition, nomagical difficult terrain doesn't impede your movement.

Credit: Jason Nguyen