Blood Jinx

You draw from the dark magic within you a card you throw at a creature. Make a ranged spell attack against the creature to assail it with the dark energy contained in the card. On a hit, the target is branded by the Blood Jinx and takes 1d8 necrotic damage, and it can't regain hit points until the start of your next turn. Until then, the Blood Jinx is branded to the target. 

If you hit an undead target, it also has disadvantage on attack rolls against you until the end of your next turn.

This spell's damage increases by 1d8 when you reach 5th level (2d8), 11th level (3d8), and 17th level (4d8).