Agonizing Rebuke

You choose one creature that you see within range that is not at full hit points and magically force it to make a Constitution saving throw. On a failure, that creature's wounds open and bleed profusely and it takes 2d6 necrotic damage from blood loss.

On each subsequent turn, the creature must make a new saving throw and take damage equal to your spellcasting attribute modifier (minimum 1) on failure. This effect ends if the creature succeeds at three saving throws (these do not need to be successive), is treated with healing magic, or is treated by nonmagical means, such as with a healer's kit.