Coral Shards

Sea shells and/or coral begin to form over the caster’s nails. When the caster throws their hands at a creature that is in sight, the coral breaks off of their finger nails and flings into the creature. The target my make a constitution saving throw or take 1d10 piercing damage. 
When you reach 3rd level add another d10, 3rd level (2d10), 11th level (3d10)z