Among Matoya's many arcane resources is a door to the Antitower, a vantage point over the aetherial sea.
How to Unlock
The Antitower 4-player dungeon is unlocked by the level 60 Main Scenario Quest The Word of the Mother.
Zuro Roggo will sometimes cast Water Bomb, a circle attack. It will sometimes cast Odious Croak, a continuous cone attack in front of it. Move out of the way of this or you will take continuous damage.
Sometimes it will cast Toy Hammer, which inflicts Concussion, stunning the player. Musical bubbles will appear periodically around the area. Stay away from these to avoid taking damage. If you are near a bubble when it explodes, you will be afflicted with Damage Down status.
Two players will be turned into toads. Defeat the Poroggo Choirtoads to dispel the transformation.
Gyrating Glare damages all players.
Ziggy summons untargetable Stardusts. They will cast Mystic Light, a circle attack centered on each Stardust. Move far away from the Stardusts to avoid the attack.
Jittering Glare targets a random player with a cone attack.
When Ziggy starts casting Jittering Jounce, the tethered player can hide behind a rock to transfer their tether to the rock. Ziggy then casts Gyrating Glare, which causes the tethered rock to perform a circle attack centered on itself, so move away from the tethered rock to avoid the attack.
Jittering Jab is a high-damage attack on the player highest on the enmity list.
When the dolls are close together, ranged DPS can use Limit Break on the six dolls to kill them more quickly, if Limit Break is available. The red Brina dolls will cast donut attacks around them while the blue Calca dolls will cast cone attacks in front of them.
After all six dolls are killed, they will merge into a giant Calcabrina doll.
Periodically, one player will be marked with a red eye. Calcabrina will cast Terrifying Glance at the marked player, which is a cone attack that inflicts Confusion. The marked player, and any players near them, should look away from Calcabrina during this attack to avoid Confusion. Confused players will hit a random ally until the effect wears off.
When Calcabrina casts Brace, it will gain a Directional Parry status that will cause players to take damage if they hit Calcabrina from one of the shielded directions. Watch closely to see which direction is safe to attack from, then stand in front of that direction before you attack. Once the boss's Directional Parry status wears off, it is safe to attack from any direction.
When Calcabrina casts Dollhouse, one random player will be transformed into a Calca doll, and another random player will be transformed into a Brina doll. The transformed players will be unable to attack and unable to control their movements. The dolls will drift around the room at random, casting a donut attack or cone attack, just like the dolls from the beginning of the battle. At the same time, Calcabrina will continually cast Slapstick, damaging all players. The players who have not been transformed into dolls should kill the dolls to free the trapped players.
Calcabrina will sometimes cast Knockout, a high-damage attack on the player highest on the enmity list.
Completing the Quest
Defeating the boss will complete one of the quest objectives for the Main Scenario Quest The Word of the Mother. There will be a cutscene. This one is important, so it is recommended to watch it either now or via the Unending Journey in an inn room.