General use of Topaz Carbuncle or Titan-Egi can mess things up and for the main part of the dungeon the ACN should really use either Emerald Carbuncle, Ifrit-Egi or Garuda-Egi. I'm just saying that on a few of the dungeon bosses Topaz Carbuncle and Titan-Egi can be a great help. it does how ever require the tank, ACN and healer to work together.