Curse of The Demon Lord

You’ve been inadvertently exposed to powerful demonic corruption; for better or worse. The Lord of Wrath, while indulgent for now, is quick to punish if you overstep your bounds.

You gain the following:

-You gain proficiency in Constitution saving throws.
-You gain resistance to Necrotic damage and Poison damage.
-On a critical hit where the Eldritch Smite invocation is used, you simultaneously take half of the total force damage dealt as Necrotic damage and lose any remaining Hit Dice you may have. The Necrotic damage cannot be reduced in any way. Additionally, until the end of your next turn, you have disadvantage on all attack rolls and ability checks.