Now that the magitek field generators have been destroyed and Livia has been defeated, you must enter the Praetorium to destroy the Ultima Weapon.
This quest is available if you have completed the quest Rock the Castrum.
Starting the Quest
Talk to Raubahn northwest of the Ceruleum Processing Plant in Northern Thanalan to begin the quest.
Speak with Cid
Go southeast to the Ceruleum Processing Plant and talk to Cid to unlock The Praetorium in the Duty Finder and Duty Support.
Use the Duty Finder or Duty Support to enter The Praetorium. Please see The Praetorium Guide for a walkthrough.
After you defeat the dungeon boss and exit the dungeon, there will be a cutscene. Then the Porta Decumana is unlocked.
The Porta Decumana
Use the Duty Finder or Duty Support to enter The Porta Decumana. Please see The Porta Decumana Guide for a walkthrough.
After you defeat the dungeon boss and exit the dungeon, there will be a cutscene.
Check on Lahabrea and there will be a cutscene, and then an instanced battle will ensue.
Solo Duty: The Ultimate Weapon (Devastation)
Ancient Fire III deals high damage and creates a ring of fire around the edge. If you walk onto the fire, you will be inflicted with a temporary Burns status.
Dark Thunder creates small circle attack markers, which will grow and leave circular puddles of darkness. Avoid stepping in these puddles.
End of Days is a large line attack.
Nightburn inflicts a Devouring Dark status.
Firesphere creates flames around the area, which will soon each have circle attacks around themselves. There will be one safe area where the flames are farther apart. Go to that safe spot to avoid the attack markers.
Ancient Eruption causes a series of circle attack markers to appear under you, one after the other. This is accompanied by Fluid Flare, which creates four cone attacks from the center. Try to drop each circle marker near the edge of a Fluid Flare cone to give yourself more room.
Ancient Cross causes four large circle attack markers to cover the middle of the area, followed by another set of large circle attacks moving outward from the first set. The areas between the two lines of circle attacks are safe at first, but then another set of circle attacks appears in the center, eventually covering the safe areas. Move carefully to the small safe spots left behind by the first set of circle attacks.
Burst Flare knocks you back from the center of the area. Move close to Lahabrea or use a knockback-prevention move such as Surecast or Arm's Length to avoid being knocked into the flames around the edge.
Grip of Night is a very large cone attack. Run behind Lahabrea to avoid getting hit.
Illusory Creation causes Phantom Lahabreas to appear around the edge. They all cast large line attacks toward the center. Move into one of the safe spaces between the lines. Lahabrea will then cast End of Days, a large line attack at you. Quickly move to a safe area to avoid getting hit by it.
He will then cast Double, and will then cast Nightburn twice, giving you two stacks of the Devouring Dark status.
Then Lahabrea casts Arcane Revelation, spawning four Arcane Spheres, while his gauge increases. Kill the Arcane Spheres one by one. Eventually, Lahabrea will trap you in chains and cast Dark Meltdown, which is accompanied by an unskippable cutscene.
After this, your movement speed is considerably increased, making it easier to dodge attacks.
He will cast Triple, then will cast Nightburn three times, giving you three stacks of the Devouring Dark status.
He will create Firespheres around the edge, so go to the center. This is followed by Illusory Creation, and the Phantom Lahabreas will cover the middle of the area with their line attacks. You will need to move to the edge as soon as the Firesphere attack markers have disappeared, to avoid getting hit by the line attacks.
He casts Dark Thunder, creating temporary puddles on the floor, and this is accompanied by Illusory Creation, so you will not only have to avoid stepping in the puddles, but you will also have to find a safe spot between the line attacks cast by the Phantom Lahabreas. Lahabrea will then cast the line attack, End of Days, so you will need to quickly find a safe spot away from this line attack as soon as the Phantom Lahabreas' line attacks have disappeared.
He will cast Ancient Cross, creating the large circle attack markers that move in lines outward from the center, which is accompanied by the large cone attack Grip of Night, which he casts from far away, so you will need to quickly move behind him as soon as there is a safe spot after the Ancient Cross circle attack.
He will cast Firesphere, accompanied by the Burst Flare knockback, so make sure to be knocked back to the safe spot between the flames. This is also accompanied by Grip of Night, the large cone attack, so you will need to quickly move behind him as soon as the Firesphere attack markers have disappeared.
After you defeat him, there will be a long cutscene.
Speak with Minfilia
After the cutscene, go east and enter the Solar. Talk to Minfilia to complete the quest. There will be a cutscene. After the cutscene, Flying will be unlocked: you will now be able to fly when mounted in La Noscea, Thanalan, the Black Shroud, Coerthas Central Highlands, and Mor Dhona. Just jump to start flying. You can change it to require a double-jump to fly, by going to Main Menu > Character Configuration > Control Settings > General Tab, under "Flying Mount Takeoff".
New Optional Quests
With the completion of this quest, you can now start many new quests, including (but not limited to):
- Mor Dhona: Legacy of Allag (first quest of the Crystal Tower series)
- Ul'dah: The Rise and Fall of Gentlemen (first quest of the Hildibrand series)
- Western Thanalan: The Weaponsmith of Legend (first quest of the Zodiac Weapon series)
Next Main Scenario Quest
After you complete the quest, talk to Minfilia to accept the next quest: The Price of Principles. There will be a cutscene.