Path of the Dragon Knight

In many worlds, there is a distinct divide between the powers of mortal and dragonkind. These are two wholly different cultures, powers, and societies, rarely intermingled. In Chromatia, however, dragons lend their power to maintaining the balance of the world's natural forces, and do so while creating a place for mortal society to participate as equals.
There is no organization that upholds this ideal more truthfully than the Dragon Knights, an ancient order of warriors blessed with draconic power to seek out and quell imbalance in the world, preventing any one dragon from claiming dominion over the others and ensuring mortals are protected from these living catastrophes' passage.
Most who consider themselves a part of the Dragon Knights do so after taking either the Oath of the Dragon Knight or joining the Dragon Riders as a Drakewarden. There are some who choose to take one step beyond these limitations, however, or perhaps ply their skills while still swearing to uphold the natural order of the world - these folk reaffirm their oaths, forging new bonds, strengthening their resolve, and honing their will through the Orb of Dragonkind to manifest a lethal Dragon Slayer, a powerful weapon in the right hands and one few earn the privilege to bear.
Those strong enough to pursue a Path may seek out the Orb of Dragonkind within Castle Reukir and swear on it to uphold the Oath of the Dragon Knights:

Protect the Balance. A member of the order will not actively hunt a dragon unless it threatens the public or the natural order. Dragons are just as much a necessary part of this world as society is.
Mercy must Prevail. Violent and lethal force must be avoided unless absolutely necessary. There is almost always another answer.
Lead with Grace. The power of dragons is a terrible thing in the wrong hands. The people should look to you for guidance, not flee from you in terror.

For paladins and drakewardens of the order, this won't be anything new. But it is still every bit a part of the ritual, and believed to strength your existing oath by reaffirming it. On completion of your oath, the Orb will bestow upon you a fragment of draconic essence, permanently branding you with draconic power. This consumes one of your attunement slots, and once completed cannot be undone by any means besides a wish spell, divine intervention, or excommunication be the order. If your attunement is ever lost for one of these reasons, all benefits of the path are lost immediately and cannot be recovered until you have redeemed yourself.
When choosing this path, be sure to note you've done so in your #character-sheets thread for reference.

Dragonmarked

You are marked with the symbol of the Dragon Knights, a living tattoo reflecting a dragon's scales that manifests somewhere on your body when you first choose this path. You gain the aberrant dragonmark feat.
Additionally, you gain a limited form of dragonsight, permitting you to connect to and commune with draconic echoes. You can cast contact other plane as a ritual. The entity you contact is an echo of one of the Great Wyrms, who are under no obligation to give you direct answers to your questions and may not be fully aware of circumstances outside of those outlined by your mission.

Dragon Slayer's Blessing

Over the course of an hour-long ritual, you may grant a single weapon the Dragon Slayer property in addition to any properties the weapon already has. If the weapon was not already magical, it becomes a +1 magic weapon while transformed. A weapon with the Dragon Slayer property deals an additional 3d6 damage to dragons on a hit (for the purposes of this effect, a dragon is any creature with the type 'dragon', including wyverns and similar creatures).
If you attempt to transform a second weapon into a dragon slayer, the first weapon reverts to its original state. These properties are also suppressed if the weapon is being wielded by a creature besides yourself.

Draconic Resilience

The power of dragons infuses itself within you, granting you resistance to one damage of your type other than bludgeoning, piercing, or slashing damage. Additionally, your Armor Class increases by 1. 
When you fail a saving throw against a dragon's breath weapon or frightening presence, you may use this ability and choose to succeed instead. Once you succeed on a saving throw this way, you cannot do so again until you complete a short or a long rest.

Nature's Wrath

Whenever you take damage other than slashing, piercing, or bludgeoning damage, you may use your reaction to instead take no damage as you capture and store it within your weapon in retaliation. The next time you hit with your Dragon Slayer weapon, it deals additional damage equal to the damage absorbed by this effect. You may use this ability a number of times equal to your proficiency bonus before you must complete a long rest.