Legacy of Black Wings

You are the embodiment of destruction, the definition of inevitability. Slowly, the crown of the ancient one walks you toward an unavoidable fate. Lean into your destiny as the embodiment of destruction for all except yourself.

You gain 2 forms, Scale Form while you do not have advantage on attack rolls, and Fang Form when you do have advantage on attack rolls.

Scale - Moonlight fills the muscles and organs of your body, covering you in a forest of black scales. You have a natural hover, which is tied to your flight speed below. Your sneak attack and related features does not require any special conditions to activate, including needing to hit with your attack roll. When you apply your sneak attack, your black scales grant you a 60ft flight speed for the combat, and, a modification on your uncanny dodge: Uncanny absorption. When you use uncanny dodge, you may use your wings to shield yourself, secretly choosing one damage type from among coatings you have on weapons you are holding or wearing. Damage of that type against you turns to healing, until the start of your turn. 

Fang - Sunlight suffuses the dormant magical centers of your body. Whenever you deal sneak attack damage, you may unleash an elemental attack alongside it on the creature. Choose a saving throw (DC equal to your initiative bonus), and on a fail, the creature takes damage equal to half it's max HP in the damage of your Helm of Elemental Mastery's last changed coating. Once it takes damage this way, it cannot take damage that way again, from that type or any other, for 10 years.

Curse of Fates - You become attuned to the Helm of Elemental mastery, regardless of the other attunements you have, the item melding into your vampiric physiology. Each time you use a vampiric ability, your blood cycles throughout your body, speeding up your thousand year transformation into the aspect of destruction. Depending on method of ascension, this fate may not be avoided (Your DM will be informed of the conditions needed to fail ascension, and to succeed. You need, min 1, a quest to ascend, on top of the TMs)