Blood Splatter

You slit your palm and splatter boiling hot blood in a 15 foot cone. Choosing how many hit points you are willing to sacrifice.  All creatures caught in the cone must make a constitution saving throw. On a failed save, they take fire damage equal to twice the hit points sacrificed.

The spell's damage increases by another multiple when you reach 5th level (three times), 11th level (four times), 17th level (five times).