as a constitution attack action, you begin to charge an attack, this charging lasts until the beginning of the next round and you cannot move during this charge, once this charge is completed, you release a blast of energy that is a 30-foot sphere that emanates from you, everyone within this sphere must make a dexterity save equal to 8+ your constitution modifier if they fail, they will the damage you've taken over the course of 4 rounds converted to radiant damage. in order for the charge to be interpreted, the attack must crit, stun, grapple ,or knock you unconscious.