Armor of the Raven Queen

You can cast this on yourself, provided you are not wearing any armor, and you will feel the protection of the Raven Queen surround you. Your base AC becomes 16 + its Dexterity modifier. The spell ends it if you don armor or if you dismiss the spell as an action.

Raven Queen's Curse.  However, after the spell ends, you must succeed on a Wisdom saving throw equal to your spell save DC.  On a failed save, you take 3d8 necrotic damage and your hit point maximum is reduced by the amount of damage taken, as inky tendrils of the Shadowfell reach out of the ground and sap your life force.  On a successful save, you take half damage and your hit point maximum isn't reduced.