You ignite the inner fire within you and your companions, stoking it into a magical flame against your enemies. A gout of fire emerges from your chest and streaks toward one creature you can see within range. The target must make a Dexterity saving throw, taking 3d6 fire damage on a failed save, or half as much damage on a successful one.    When you cast this spell, up to three friendly creatures within 30 feet of you that can see you can each use a reaction to lend its heartfire to yours. For each creature that joins its heartfire with yours, the spell’s damage increases by 1d6.