how to balance this? Spiritualism: Spirit Infusion
Inject your spiritual power into your weapon and transfer it into your target creating death marks. After Stacking Death Marks up to 10 times with your basic attack you can use the action 5 fingered death to hit an enemy with a palm strike which deals 1d4 force damage at level 1 2d4 at level 5, 3d4 at level 15, and 4d4 at level 20 per stack. Due to the strain this technique places on the users spirit can only use it once per long rest.