Dragon Rush

you charge an enemy and power your strike with your dragon spirit.  As part of the casting of this spell, make a melee weapon attack against a creature.  On a hit, the weapon deals an additional 4d6 fire damage to your target.  Additionally, that creature must succeed on a constitution saving throw or be stunned until the end of your next turn.

At higher levels:  when you cast this spell using a spel slot of 3rd level or higher, increase the damage from this spell by 1d6 for each spell level above 2nd.