Dragoness Gift

You wield black lightning using two fingers, launching it or slashing with it. Make a ranged or close spell attack against the target. On a hit, the target takes 2d6 lightning damage. A breakable object hit by this spell is destroyed if it isn't being worn or carried, if so the wearer takes 3d6 lightning damage. If a foe is hit with 5 or more damage from this spell they are knocked prone (exception: the foe is huge or bigger). This spell is to be used by people with a blue or bronze  draconic blood line.

This spell's damage increases by 1d6 when you reach 3rd level sorcerer (4d6), 4th level sorcerer (5d6), and 5th level sorcerer (6d6), 6th level sorcerer (7d6).