Path of the Dragon Heart

Within the Dragonborn Barbarian's heart lies the ancient essence of their lineage, awakening in battle. Attuning their primal rage, they embody dragon prowess, a force of nature on the battlefield. Threats of blades and spells now shrugged off. Tapping the draconic wellspring, they wield magical energies, enhancing their strikes and dominating foes. Surging with power, mighty wings unfurl, taking flight like mythical dragons by wielding their breath unleashing elemental fury upon challengers. Their spirit manifests the indomitable might of dragons, an awe-inspiring sight. The world trembles beneath their feet, for they are the legacy of a powerful heritage, destined to soar higher and burn brighter than any other.
Restriction: Dragonborn Only
Only Dragonborn who have chosen the barbarian class may follow the Path of The Dragon's Heart. In this world, the methods of emulating a
dragon are accessible only to those who bear a likeness to them. Furthermore, one of the features in this subclass exclusively affects a
racial feature unique to the Dragonborn race.

- Invicible Dragons: Unyielding Wrath

Mighty dragons boast an array of defenses, nearly invulnerable to mortal folly. Colossal bodies, armored with iridescent scales as hard as steel, form an impenetrable fortress against lesser beings' blades. A mortal's strike may glance off their shimmering hide, like a spark on stone. But their durability goes beyond their forms. Dragons possess a profound connection with arcane energies, flowing through their very essence. This bond renders them impervious to spells and manipulations, as keepers of primal magic, architects of forgotten incantations.

At 3rd level, When you enter into a rage, your rage damage is converted to match the damage type of your Draconic Ancestry. Additionally, while raging, you gain bonus points to your Unarmored Defense equal to your rage damage, and you also gain advantage on saving throws against spells and other magical effects.

- Majestic Spellcasters: Dragon Sorcery

Dragons reign as unrivaled masters of magic. With scales infused by arcane energies, these majestic beings wield spells of awe-inspiring might. From scorching flames that engulf foes to ancient incantations shaping reality itself, their mystical prowess is unparalleled. Within the clash of scales and the dance of spells, the true essence of dragons' magical might shall forever captivate the hearts of adventurers.

At 6th level, you learn to use magic, deepening the connection to your ancestral prowess. You gain access to magic as a 1st level sorcerer, without committing to a specific sorcerous origin. Additionally, as a barbarian, you can use cantrips and spells learned this way even while you are in a rage.
However, if a cantrip or spell requires concentration, entering in a rage while concentrating will end the spell. Otherwise, if a cantrip or spell requires concentration and it is casted while raging, such requirement is replaced by maintaining rage.

- Mighty Soar: Breath and Wings

Within the heart of a dragon resides the awe-inspiring power of its breath, a torrent of flames or icy frost that engulfs all in its path. Majestic wings, vast and strong, carry the ancient creature through boundless skies, defying gravity's embrace. With breath and wings united, a dragon soars in grandeur.

At 10th level, you gain a pair of wings that grant you a flying speed equal to your movement speed. Additionally, while you are raging, your breath weapon gains an additional 10ft to its range and an additional dice of damage. You may also use your breath weapon a number of times equal to your constitution modifier before you must take a short or long rest.
Finally, you obtain two additional 1st level spell slots.

- Dragon Heart: Raging Spirit of the Dragon

“At long last, it dawns on me—the meaning of a Dragon Heart. It's not just the thrill of adventure or courage in my veins. It's an indomitable spirit, ablaze with ancient wisdom and strength. As I embrace this newfound understanding, I attain spiritual ascendance. Now, with wings unfurled and heart ablaze, the dragon's might shall make known its presence to foes and friends alike."

At 14th level, you learn to summon a draconic spirit casting it from your rage. By using your action to enter into a rage, you may choose to cast the spell “Summon Draconic Spirit” as a 5th level spell. The family of the draconic spirit is tied to your Draconic Ancestry, and the duration of the spell lasts as long as you are raging. The concentration requirement is replaced by maintaining rage.
Using this ability still counts towards your rage usages. If you have unlimited rages, you may use this ability six times before you must finish a long rest.
Finally, you obtain two additional 1st level spell slots.