Vander's Mind Scrambler

You create three incorporeal spikes that lash out towards three seperate target enemies in range attempting to pierce and scatter their thoughts. Each creature must make a Int saving throw. on a fail save they take 3d6 psychic damage and are stunned till the start of your next turn, you may on your turn as an action force each creature effected to make another saving throw and repeat the cycle. If they succeed they only take half damage and they are not stunned and they cannot be forced to make anymore saves. 

When you cast this spell at 5th level, it creates one additional spike and they deal and additional 1d6 psychic damage.

7th level spell slot , you create a total of 5 spikes and each deals a total of 5d6 damage

9th level spell slot, you create a total of 6 spikes and each deals a total of 6d6 damage