Galvanic Blast

You extend your hand outward and unleash an arc of blue lightning. Each creature in a 15 foot line must make a Dexterity saving throw. A creature that fails the save takes 1d6 lightning damage and can’t take reactions until the start of its next turn. A creature wearing metal armor has disadvantage on the save.

This spell's damage increases by 1d6 when you reach 5th level (2d6), 11th level (3d6), and 17th level (4d6).