Spark Rune

Effect: The caster inscribes a rune that releases a spark of lightning up to 60 ft away targeting the creature’s Will. On a hit, the target takes 1d8 Lightning damage and is StunnedStunned ConditionThe target cannot take Actions. Any attack against it yields Advantage, the target doesn’t count toward flanking, and if it is a target with natural flight it falls. until the end of their next turn. 

At 5th, 11th, and 17th level this spell gains an additional damage die (2d8, 3d8, 4d8).