tap dance of thunder

You have been dancing since the day you learned to walk. You have become one with dancing, and you have learned how to attack using dances. You put on your tap shoes and start dancing. Every time your foot hits the ground, a thunder wave strikes all around you. Every creature within 15 ft. takes 1d8 thunder damage every wave that hits them. The creatures must succeed on a DC15 dexterity saving throw for every lightning wave. Roll a d10 to find out how many waves you create. At the end of the dance, every creature hit by at least one lightning wave makes a DC10 constitution saving throw. On a fail, the creature is paralyzed.