During the terrible Liche War that laid low the island nation of Inuitea around 100 years ago, the wicked Xaphan and his Cult of Neistra'demos came upon the ancient silver dragon Amrost and her devoted progeny, the dragonborn. Unknown outside of this enclave, the dragonborn had few allies to call upon and were quickly overwhelmed by Xaphan's undead legions. Rather than slaughter the dragonborn wholesale and animate them as mere skeletal or zombified troops, the exarch of Neistra'demos had another fate in mind.
Amrost was made to undergo the vile rites of the dracolich in order to spare the lives of her dragonborn. The once-glorious silver dragon became a terrible undead monster under Xaphan's control, with the dragonborn's mystical bond to their matron intact. Instead of troops of rotting flesh and cracked bone, Xaphan manipulated the dragonborn to serve in his armies as elite shock troops with icy breath weapons and impressive brute strength.
Proximity to the terrible necrotic magics used by Xaphan, as well as their connection to Amrost, slowly turned the shining scales of these dragonborn to a dull grave-gray, and their golden eyes into hollow yellow pits. Though not undead themselves, the dragonborn were tainted by it forever, and when Amrost was slain by mortal champions, the lichebound dragonborn were left without a home, without a master, and without hope.
Though few of them remain, the last lichebound dragonborn are tragic souls wandering a world that fears them for crimes not of their making. They can be found in Manifest from time to time, researching ways to reach across to whatever afterlife dragons go to and bring Amrost back to the world. Others have given in completely to despair, becoming necromancers themselves. As they are humanoid, dragonborn can indeed become ghosts.
Ability Score Increase. Your Strength score increases by 2, and your Intelligence score increases by 1.
Age. The only living lichebound dragonborn are well over 100 years old. They have no known upper age limit.
Size. Lichebound dragonborn are tall, but gaunt. You stand anywhere between 6 to 7 feet in height and weigh around 200 pounds.
Speed. Your base walking speed is 30 feet.
Necrotic Breath. You can exhale a 15 foot cone of necrotic vapor. Creatures in the area of effect must make a saving throw with a DC equal to 8 + your Constitution modifier + your proficiency bonus. A creature takes 2d6 necrotic damage on a failed save, and half as much damage on a successful save. The damage increases to 3d6 at 6th level, 4d6 at 11th level, and 5d6 at 16th level.
Necrotic Resistance. You are resistant to necrotic damage.
Inured to Undeath. You have advantage on saving throws against effects originating from undead that cause the frightened condition, or which reduce your maximum hit points (such as the enervating touch of a wraith).
Languages. You can speak, read, and write Common and Draconic.
They are pretty similar to existing dragonborn, but themed around undeath due to their history. Though necrotic damage is a relatively common energy type used against players, it is either partially or completely useless against a common enemy of player characters (the undead, of course). The resistance was thus good, but the breath weapon only occasionally so.
Thus, I felt it prudent to give them an extra trick, Inured to Undeath. It might not be good enough, but I'll build on it as I continue my work.
Other races to be added include the deathwarden dwarf subrace (the clan that lives beneath Manifest), the spirit elves (who protect and live near to the Spirit Wood), and an attempt to update the vryloka from late 4E.