It is now your mission to infiltrate Castrum Meridianum and power down the magitek field surrounding the Praetorium, where the Ultima Weapon is housed.
How to Unlock
The Castrum Meridianum dungeon is unlocked by the level 50 Main Scenario Quest Rock the Castrum.
A Note About Unskippable Cutscenes
This dungeon is one of a small number of duties in Final Fantasy XIV that contains unskippable cutscenes. Because of this, the dungeon may take slightly longer to complete than other dungeons. During these cutscenes, the dialogue will advance automatically and cannot be skipped.
Arrive at the Central Crossing
Defeat the enemies in the path to lower the barriers in the way.
The Black Eft
When the Black Eft begins to glow brightly while casting High-Powered Magitek Ray, make sure not to be in front of where the Black Eft is facing, to avoid getting hit by the attack.
Incendiary Support damages all players.
Request Assistance summons new enemies, so be sure to use multi-target attacks to get rid of them quickly.
Magitek Cannon is a circle attack at a random player.
Arrive at Area V
Go to the Disposal Chute in the southeast of the boss area. Interact with it to proceed. Then go up the stairs and go northwest. Defeat the enemies while dodging the large circle attacks that hit random locations. Defeat the enemies ahead to lower the barriers.
Magitek Vanguard F-1
Thermobaric Strike places a proximity indicator in a corner of the area. Move to the opposite corner to minimize the damage that you take from this attack.
Hypercharge is a large attack where the only safe area is a small ring around the boss. Stay in the safe area to avoid the attack.
Cermet Drill is a high-damage attack on the player highest on the enmity list.
Overcharge is a cone attack in front of the boss.
Targeted Support hits all players with a circle attack.
Arrive at the Parade Ground
Proceed onward and kill the enemies that appear in front of the gate. Afterward, go through the opening and follow Cid. Defeat the enemies, and eventually there will be an unskippable cutscene.
Livia sas Junius
Artificial Plasma damages all players.
Roundhouse is a large circle attack centered on the boss, which also causes circle markers to appear all around the edge a moment later. Get away from the central circle attack marker, then as soon as it disappears, go back into the center to avoid getting hit by the attacks around the edge.
Aglaea Climb is a high-damage attack on the player highest on the enmity list.
Infinite Reach makes a large number of line and circle attack markers appear. Look carefully for safe spots to run to. The attacks may overlap, so be sure to stand on the attack markers that appeared second, and run to where the first attack markers have just disappeared.
Sometimes Livia goes to the center and casts Angry Salamander, creating several line attack markers going outward from her.
Thermobaric Strike will either create two or four proximity indicators. If there are two, they are accompanied by Stunning Sweep, which creates a large number of circle attack markers. Find a safe spot between the circles, then when possible, go to either the west or the east edge so you are as far away from the proximity indicators as possible.
If Thermobaric Strike creates four proximity indicators, it is accompanied by Angry Salamander. Avoid the line attack markers, then move to the center of the area so you are as far away from the four proximity indicators as possible.
When Livia's health is low, she uses Artifical Boost, which increases her defense. She will repeatedly attack with Artificial Plasma, damaging all players. Do as much damage as you can, as quickly as you can, to avoid allowing your health to become too low from Livia's repeated attacks.
Completing the Quest
Defeating Livia will complete one of the quest objectives for the Main Scenario Quest Rock the Castrum.