Boiling Blood

You attempt to superheat the blood of a creature you can see within range. The target must make a Constitution saving throw. On a failed save, the target takes 4d6 fire damage and is afflicted with the Curse of Crimson Agony until the end of your next turn. While under this curse, the target has disadvantage on concentration checks.

On a successful save, the target takes half damage and isn’t cursed.

Creatures without blood are immune to this spell.

Blood Sacrifice. When casting this spell, you take 2d4 damage as your blood momentarily heats in sympathy with the target.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d6 for each slot level above 2nd.

The Curse of Crimson Agony Victims have disadvantage on concentration checks. The duration varies by the spell or effect that applied the curse.