Dragon Knight

The fighters of order of Dragon Knights is one both ancient and revered. Elite warriors of the Dragonborn cities, the Dragon Knights are those of potent sorcerous potential that decide to dedicate their lives to martial combat rather than the arcane, but still use their sorcerous magic to enhance their combat abilities.

Prerequisite

Only Dragonborn can become Dragon Knights, though your DM may allow Draconic Bloodline sorcerers of any race to play this subclass if they're willing to modify the class attributes a little.

Draconic Surges

At 3rd level, when you choose this archetype, you learn the ability to manifest your magical blood into surges of Draconic power. You gain a number of Draconic Surges equal to your Charisma modifier + half your Fighter level (rounded down). At the start of your turn, you may expend as many Draconic Surges as you wish in order to manifest 1 or more of the following effects. You may also expend multiple surges on the same effect to increase its potency. These effects last until the start of your next turn. You regain your Draconic Surges at the end of a short or long rest:

You can add 1d4 damage to your melee attacks, the damage type is the same as your Draconic Ancestry (damage increases by 1d4 for every additional Draconic Surge expended)

You can add 1d6 damage to your Breath Weapon, extra damage is the same type as your Breath Weapon (damage increase by 1d6 for every 2 additional Draconic Surges expended)

You gain 60 ft darkvision (range of darkvision increases by 15 ft for every additional Draconic Surge expended)

You may give an ally resistance to the same type of damage as your Draconic Ancestry (does not scale with No. of Draconic Surges expended)

You can change the shape of your Breath Weapon, cone becoming line and vice versa (does not scale with No. of Draconic Surges expended)

Imposing Aura

At 7th level, you have learned the ability to imitate the awe-inspiring or fearsome presence of a Dragon. You may spend 3 Draconic surges in order to create an aura of fear or awe (your choice). Every creature of your choice within 10 ft of you must succeed a Wisdom saving throw against your DC of 8 + your proficiency bonus + your Charisma modifier or become Frightened or Charmed for 1 minute. A creature may repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to your Draconic Presence for 24 hours. Your auras range increases to 20 ft at 10th level and 30 ft at 15th level. For every extra Draconic Surge you spend on this ability, the range of the aura increases by 5 ft.

Elemental Rapport

At level 10, your control of Draconic magic is extended to effects outside of your body. Whenever you take 15 or more damage of the same type as your Draconic Ancestry, if spent, your breath weapon recharges, and you release it as a reaction. In addition, if an ally within 30 ft of you takes the same type of damage type as your Draconic Ancestry, you may use your reaction to spend 2 Draconic Surges to take half of the damage (resistance does not affect damage taken).

Dragon's Resilience

Upon reaching 15th level, you gain the ability to harness the innate defenses of your Dragon Ancestor. You gain immunity to the damage type of your Draconic Ancestry.

Draconic Soul

At 18th level, your Draconic abilities have reached their apex as you reach the limits of your power. Upon taking damage of the same type as your Draconic Ancestor, you heal half (rounded down) of the damage that would be taken. You also gain the ability to once per day choose to succeed a saving throw when you would otherwise fail.