Boil Blood

Choose a living creature that you can see within, you cause their blood to boil. When you cast the spell, the creature must do a Constitution saving throw and take 2d8 fire or necrotic damage if it fails, or half the damage if it succeeded. Until the spell ends, you can use your bonus action on each of your subsequent turns to cause this damage again if you see the creature and if you are in range. The creature must repeat the Constitution saving throw each time to half the damage on a success.

The creature must succeed a Constitution saving throw or have disadvantage on attack rolls and ability checks until the spell ends. It can repeat the saving throw at the start of each subsequent round. If they succeed, the disadvantage is cancelled.

Moving outside of range from the affected creature does not end the spell.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the damage increases by 1d8 for each slot level above 2nd.