Defy Death for Profane Power
You've made a pact with a creature that defies the cycle of life and death: a powerful lich, a vampire, or another entity of undeath. Having once been mortal, these ancient patrons know firsthand the paths of ambition and the routes past the doors of death. They eagerly share this profane knowledge and other secrets with those who work their will among the living.
Form of Dread
As a Bonus Action, you transform into an avatar of your patron's dreadful power, gaining the benefits below for 1 minute, until you have the Incapacitated condition, or until you end the form (no action required). You can transform a number of times equal to your Charisma modifier (minimum of once), and you regain all expended uses when you finish a Long Rest.
Facsimile of Life
You gain Temporary Hit Points equal to 1d10 plus your Warlock level.
Fearless Form
You have Immunity to the Frightened condition. If you are Frightened when you transform, the condition immediately ends for you.
Frightful Avatar
Once per turn, when you hit a creature with an attack roll, you can force it to make a Wisdom saving throw against your spell save DC. On a failed save, the target has the Frightened condition until the end of your next turn.
Undead Spells
The magic of your patron ensures you always have certain spells ready; when you reach a Warlock level specified in the Undead Spells table, you thereafter always have the listed spells prepared.