The player should watch out for its Marking ability during their first encounter, which lowers down all status levels by ten percent to a single ally for four turns. Due to the fact the enemy is weak to wind-elemental attacks; the player can easily defeat the enemy by having the party cast the Aero spell.
When encountered in the Holy Tree Tower bonus dungeon, Cu Siths retain the Marking ability and are now immune to the earth element. The enemy has no elemental weaknesses, so the player should attack with the Hero's Bladeblitz ability and the Black Mage’s Magic Might ability. The other party members should be using healing items and Curaga to heal damaged allies.