Nightmare of Caiatl, Princess-Imperial

The Nightmare of Caiatl, Princess-Imperial is the Nightmare at the center of Emperor Calus' mind and serves as the final boss of the Duality Dungeon.

Gameplay
To start the encounter, one player has to run down the stairs of the spawnpoint, which causes the Nightmare and several battalions of Cabal to spawn. To progress in the fight, players must kill pairs of Honored Bellkeepers to allow Bells of Conquests to be activated.