Aether Sting

Make a ranged spell attack against any creature in a 20' line of you. That creature must succeed on a Wisdom saving throw versus your spell DC, on a successful save nothing happens. On a failed save That creature takes 1d4 Psychic damage immediately and must reroll the save at the beginning of each of their next turns taking 1d4 Psychic Damage on each fail. If the creature succeeds at any point against this spell it is then immune to the spell for 24 hours. 

(At your level 8, 12, 16, & 20 add an additional d4)