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 50-foot sphere that emanates from you, everyone within this sphere must make a dexterity save equal to 12+ your constitution modifier if they fail, they will the damage you've taken over the course of 10 rounds converted to radiant damage. the only way for the charging to be interrupted is for a critical attack to land