Tris' Void Dart

You conjure a dagger of whirling grey energy. Make a ranged spell attack against a target. If the attack hits that target takes 2d4 force damage and must succeed a constitution saving throw. On a failed save the creature is stunned until your next turn. 

At Higher Levels: When you cast this spell slot of 2nd or higher, the force damage increases by 1d4 and you may choose an additional target for each spell slot above 1st.