Walkthrough Part 2[]
From the savepoint, return to the Sealed Temple and enter through the double doors at the bottom. In this area you can meet up with various dragons (red, blue and yellow) as well as Assassins and Mini Satanas.
Head to the left and take the bottom path. Follow it round and pick up a Dark Matter, Holy Water and a Hero's Cocktail. You'll arrive in a large open area. To the north is a corridor blocked by a large stone statue. Examine the statue. There is a secret passage on the right side of the open area leading to a chest containing the Gladius, a powerful dagger that I never found a use for.
Once you have examined the statue, head back out and save. If you didn't save before, save now. If it is your first time fighting this boss, you will die at least once. If it is not your first time, you will probably still die at least once. The next boss is hard.
Remember the Hall of the Watchmen? Head back there, and take the north path this time. You'll find a man offering you a potion that lasts for hours on end and can soften petrification curses even gold needles bounce of. If you have examined the statue, he'll offer you some, with a catch - by 'hours on end' he meant 'five minutes'. Much like in Karnak Castle after the Liquid Flame, you are now on a timer.
Head to the warp point, and arrive in the Ruined Shrine. Follow the path to the outside of the Sealed Temple, and then enter the double doors again. Head back to where you found the statue. If you have the Chicken Knife, run from all the random battles with Teleport or !Flee. If you have Brave Blade, take care of all encounters quickly with !Zeninage or Dualcast Syldra. You want to make it to the statue with at least a minute remaining so you can prepare.
I'm assuming you're already using an ability setup much like I recommended in Preparation, which will be fine for this boss. There are two ways you could equip your accessories; give everyone Angel Rings, or give three people Angel Rings and your blue magic user Hermes Sandals. Once you're ready, examine the statue again.
Boss Fight: Grand Aevis[]
The first indicator of how hard the fight will be is the music, which is the Decisive Battle, rather than the boss battle theme. Secondly, the Grand Aevis is accompanied by two Dark Elementals. They have two attacks; Aeroga and White Wind. Aeroga can deal almost 2000 damage, and the Dark Elementals have 5500HP to use for White Wind. Yeah, they've got to go.
Start with a Mighty Guard to cut Aeroga (and most other) damage in half. The Grand Aevis himself can use Zombie Powder, Maelstrom, Blaster, Poison Breath, Evil Eye, Breath Wing, Wing Attack and Paraclete. Paraclete is a new ability that revives a character as a Zombie; however, if you have Angel Rings, it will revive the character just like a Phoenix Down, and the Grand Aevis is still dumb enough to use it. Zombie Powder turns the target into a zombie, hence the Angel Rings; Poison Breath will damage and inflict Poison, Evil Eye will inflict petrification, and Blaster can inflict paralysis or death, so Ribbons may also be helpful in the fight.
Cast Hastega on yourself and try to get Slowga on the Grand Aevis. The Dark Elementals are weak to Wind and therefore Syldra, but the Grand Aevis absorbs it, so Dualcast Bahamut to get rid of them. However, the next time you hit the Grand Aevis but don't kill it, it will revive them, so the next hit needs to do as much damage as possible. I use Flare Spellblade and Rapid Fire for this purpose. When the Dark Elementals are revived, Dualcast Bahamut to remove them again, and then repeat until the Grand Aevis dies, healing when necessary.
When the Grand Aevis is dead, you are free to proceed further into the Sealed Temple. However, I would go back to the start to heal and save first.
Follow the path behind the Grand Aevis to the stairs to the next area, but before that, go to the right and up, to collect the chest next to where you found the Gladius. It contains an Ether. Now head into the next area, the Heart of Ronka.
Of note, the entire Ronka area is infested with Exorays. These will kill you, very quickly and very painfully, unless you kill them quicker. Zeninage or Odin are the best ways to do this; they come in groups of five and, much like the Gargoyles or Movers, they will respawn if they are not all defeated at the same time. Exorays can use Paralyse Powder, Darkness Powder, Poison Powder, Confuse Powder, Silver Powder and Zombie Powder, all of which inflict heavy damage and the status effect of the same name (Silver Powder inflicts Old), as well as Firaga.
The first area is the treasure room. Most of the treasures here are consumable items such as Shuriken, Mix and Combine ingredients. Collect the four treasures where you start, then head south to collect two more. Head south again to find three more treasures, one of which is the Sorcerer's Mantle, an accessory that halves damage from elemental attacks (The item description claims it nullifies elemental attacks, but it's a lie, though we do get a piece of equipment that does that later).
Head back to the centre and then to the left, to collect some more treasure. Head south from here to B2. Go all the way south and you'll reach a treasure chest arrangement like you found in Ghido's Cave, where you have to place a rock in different chests to open doors. The bottom right and top left chests will open to the two leftmost doors, allowing you to pick up a Hyper Wrist and some Combine ammunition. Then place it back into the centre chest and return to the treasure room.
Head all the way to right to find some more treasure, then south back to B2. Be careful not to fall down the holes, and open the chest containing the Kagenui. Now, fall down the top right hole, and you will arrive in B3. Head to the right and then down, picking up a Cottage on the left. Then, enter a secret passage to the right, and follow it round to find the Apocalypse, a sword stronger than the Ragnarok.
Go around the chest and enter the secret passage to the left. Follow it, and you'll arrive in a small room with a chain going down. Hop onto the chain and you will arrive in B4. Head to the right, past the other chains, and then go up until you find another one. To the right is a warp that will take you back to the very start of the dungeon; remember that for later. For now, go up the chain.
From here, go to the left, and then up. Go to the left again, and then down a very long staircase which leads to the Abyssal Falls, and the third part of this walkthrough.