Ethereal Knife

You conjour then throw an ethereal mote of psychic energy that muddles the mind of the target. Make a ranged spell attack against the target. On hit, it deals 1d8 Psychic damage and they must deduct 1d4 on the next ability check they make until the end of there next turn.

At higher levels you create more then one Ethereal Knife: two Knives at 5th level, 3 Knives at 11th level, and 4 Knives at 17th level. You can aim them at the same target or at diffrent ones. Make a separate attack roll for each Knife.