Cardiac Resonance

You hammer a nail or screw into the ground causing a shockwave that tenses and shocks the hearts of surrounding creatures within a 15ft radius. All creatures within the radius that you can see must make a CON save against your spell DC or take 1d6 necrotic damage and fall to their knees prone. On a success they only take half the damage. The number of creatures in the radius which can be affected corresponds to the character's level. If there are more creatures than the characters level, you decide which hostile creatures to target and which are not affected.