Blood Boil

Choose one creature with blood within range. You focus in upon their internal structure, and they take 4d8 fire damage. On your turn, you can spend your action to deal another 4d8 fire damage, or alternatively use your bonus action. If the bonus action is used, the creature makes a constitution saving throw on your spell save DC. On a failure, deal 4d8 fire damage. On a success, the spell ends.

At Higher Levels. When you cast this spell using a spell slot of 5rd level or higher, the damage increases by 1d8 for each slot level above 4nd.