Blood Boil

As an action you speak words malice that would boil a creatures blood. Choose one creature within range to make a Constitution saving throw. On a fail the creature takes 2d12 fire damage and has disadvantage on attack rolls and ability checks for the duration of the spell. On subsequent turns you can use your action or your bonus action to immediately re-inflict the initial damage. The spell ends if you use neither. The creature makes the saving throw again at the end of each of it's turns, ending the spell on a success, and it does so with advantage if you used your bonus action to upkeep the spell. The spell also ends if the creature gains total cover from you or if it exits the range of the spell.

At higher levels: For every spell slot you use to cast this spell above 3rd level the initial fire damage increases by 1d12