The painting of Emperor Gestahl in Jidoor revealed the location of the Phoenix Cave, but you want to be well-prepared before you attempt to delve this dungeon. You'll need to bring two parties, which means eight well-equipped Characters. There are two major prizes here, the Phoenix Esper and Locke, as well as one of the eight legendary dragons. The Monsters are fierce, but the Treasures are worth it. To enter the Phoenix Cave, position the Falcon over the small opening in the pentagonal mountain range north of Tzen, then press .
You can return to the Falcon by grabbing the crane on the Landing, but Warp will not work within. Note that if you leave in this way, your party will be reverted to just Setzer, which might be a problem if you go flying off and run into Doom Gaze. You can swap between parties within the Phoenix Cave at any time by pressing .
Encounters in the Upper Cavern
There are two large chambers in the Phoenix Cave, each with its own aesthetic and different Encounters. The upper cavern is a traditional cave and features a wide variety of Monsters. The most common of these are Phases, which often appear in pairs. They are similar in appearance and actions to Brainpans—they use Smirk to cause Stop in addition to making moderately powerful attacks, and they can use Blow Fish when they are alone on the battlefield. Phases can also use Blow Fish as a general counterattack. They are vulnerable to Ice like many denizens of the Phoenix Cave, and absorb Fire.
Parasouls can appear alongside a Phase and a pair of Necromancrs. Parasouls are vulnerable to Fire and have lower HP than most of the Monsters in the Phoenix Cave. They can cause Muddled with Spin Slice and use Flash Rain for moderate damage. They will use El Nino, an attack twice as powerful as Flash Rain, if they are the last Monster standing. All of the Monsters they appear with grow more powerful as the last foe standing, so you may have to pick your poison in this grouping.
Necromancrs are one of the few Monsters in the area that are neither weak against Ice nor absorb Fire. As undead, they are actually weak against Fire as well as Pearl. Their basic attacks are reasonably dangerous and they can inflict Zombie with ZombiStick They can counter anything but Fight with Demi or Quartr, and will go especially crazy when their allies have perished, casting Doom, X-Zone, and Flare. Flare will deal over 1,000 damage, and both Doom and X-Zone can outright Wound anyone not immune to them.
Trixters also appear with Necromancrs. Their only offense in most circumstances is the occasional use of Fire 2, but they will respond if any creature on the battlefield gains Reflect. They'll bounce Cure 2, Rflect, or Haste off of your party, or all three levels of Fire off of their own. Aside from Necromancrs, they're the only other Monster in the Phoenix Cave that is not vulnerable to Ice. Their only weakness is Pearl, though the Man Eater is also effective since they are human.
Finally, there is the rare encounter with an Aquila and two Chaos Drgns (see the below section for notes on Chaos Drgns). Aquilas are noteworthy because if you bring Locke back here after you recruit him, he can steal an amazing Economizer from them 1/8 of the time. Aquilas usually make strong basic attacks, occasionally mixing it up with specials.They can use the brutal damage special Flap on turn 2 and Cyclonic on turn 3, and they repeat their sequence after 4 turns. Like Vultures, they also like to counter attacks with Shimsham. They have plenty of HP but are vulnerable to Ice. They are easier to kill than Chaos Drgns and usually more dangerous, so take them out first.
Encounters in the Lower Cavern
The Lower Cavern of the Phoenix Cave has a lava theme, and every Monster that appears down here is vulnerable to Fire and absorbs Ice except the returning Trixters, who appear in threes. Chaos Drgns are more common on this level, appearing with an Uroburos and two Sea Flowers. Chaos Drgns act only rarely, potentially using Disaster to inflict various Statuses including Imp, Mute, and Muddled on their second turn. On their sixth turn they can use Cinderizer to immediately Wound a target. They have over 9,000 HP but are highly vulnerable to physical attacks. Since they generally don't do anything, other Monsters usually take priority.
Sea Flowers can appear on their own in groups of five as well as with Uroburoses and Chaos Drgns. They are susceptible to Thunder in addition to Fire. They lack any interesting attacks, occasionally inflicting Poison with Feeler but offering no counterattacks or other Abilities to be aware of.
Uroburoses always appear alongside a pair of Sea Flowers, and usually with a Chaos Drgn as well. They have incredibly high Defense and Mag.Def but only 50 HP. Any Defense-ignoring attack will take care of them immediately. They can cast Bio in the second round of combat, and turn someone into a Zombie with Doom Touch in the fourth.
Navigating the Phoenix Cave
Your parties start off next to one another, but will be split up almost immediately. One party must stand on a switch just inside the entrance which opens the western door. We'll call the party on the switch party 1, and the party that goes through this door party 2. There's a treasure chest east of the door, but a pit trap will drop you to the Lower Cavern onto a bed of spikes that deals 500 damage to each party member if you try to open it. There are more spikes to the north, so for now you'll want to go south to the cavern where party 1 is standing on the switch. There's another switch on the upper level; stand on it with party 2 to allow party 1 to exit through the eastern door.
Randomly strikes mortal blow
Party 1 will see another switch to their north, just below the series of spikes blocking party 2's way. Stand on that to retract the spikes, and switch to party 2. They can now access a staircase down to the Lower Cavern where they would have fallen had they tried to open the chest earlier. Head south to the stairs back up and hit the switch to create a bridge that allows access to that chest, which contains a Wing Edge. Then circle back around to the spikes (which should still be retracted) and head east and south to a switch that retracts a set of spikes for party 1. This allows them to access a staircase to the south as well as a chest to the east. The chest is empty, a sign that a certain treasure hunter has already been through this dungeon.
In the Lower Cavern, party 1 should head northwest to hit a switch that opens a path across the lava for party 2. They'll find another empty chest in the vicinity as well. Head back to the island with the stairs, then follow the bridges southeast instead. They soon turn north, passing yet another empty chest. Eventually they will reach a dead end. Switch to party 2 and return to the Lower Cavern, crossing the newly created path of jumping stones.
Party 2 will see a chest behind some spikes up ahead. Predictably, it is empty. You'll have to take the damage if you want to open it, these spikes cannot be retracted. Step on the switch near the edge of the lava to move the giant rock and allow party 1 to head north. Party 1 will ascend to the Upper Cavern but are blocked by another series of spikes, so head back down through the other exit and step on the switch that moves the rock back to its original location. Party 2 can now pass as well.
Party 2 will see the save point you may have noticed earlier when they ascend to the Upper Cavern. There is a bug in the game where if you stand on the save point and switch parties, you can use a Tent with the party that isn't on the save point. Whether to take advantage of this bug is up to you, but saving is probably a good idea in any case. The switch to lower the spikes blocking party 1 is to the north.
With the way opened, party 1 can head past the spikes and return to the Lower Cavern. This area is filled with a grid of stones you can hop across. There is a chest in the middle you can't reach yet. When you reach the southeastern platform, the western rocks lead to an empty chest while the eastern ones lead back up to the Upper Cavern.
This area is flooded, but a switch on the wall will drain the water. In addition to opening up several new paths in the Upper Cavern, this cools the lava below in the Lower Cavern, which will open its own path shortly. A series of square rocks blocks party 1's path, so switch to party 2 once more. There is a switch west of the save point, near where party 1 is blocked, which will allow party 1 to pass to the south. Stand on it, and switch back to party 1.
Party 1 has several paths they can take, but for now proceed further south. You'll see a chest containing the Dragon Horn guarded by the slowly wandering Red Dragon, one of the eight legendary dragons. Defeating it will earn you the Strato, a powerful Weapon for Cyan. Ice Shlds and Flame Shlds both serve to protect you from most of the Red Dragon's magic attacks. (Note that if you would rather have party 2 take on the Red Dragon, there is an opportunity to swap the parties coming up shortly.)
The Red Dragon starts off by using Fire 2 and Fire Ball, both for significant damage. It will counter 1/3 of attacks with its own powerful attack. Once you've gone through about 2/3 of it's 30,000 HP, it will upgrade its spell list, favoring Fire 3 and Flare. Note that Flare is non-Elemental, so Elemental shields won't protect against it. It ignores Mag.Def, but MBlock% still offers a defense against it. Since the Red Dragon's Flare deals around 2,000 damage, any defense you can get is a good thing. The Red Dragon does not take kindly to use of Reflect, responding by removing it and dealing damage with Eraser.
As you might expect, the Red Dragon is vulnerable to Ice and Water, and absorbs Fire. Try to defeat it quickly, as approximately every 40 seconds it will use either S. Cross, L.4 Flare, or Flare Star as the battle wears on. All are powerful attacks that hit the whole party, though only L.4 Flare among them is non-Elemental.
When the Red Dragon is defeated (or avoided), have party 1 head back north to the plateau with three switches. Have them stand on the northern switch to create two rocks nearby, then switch to party 2. When they move from the switch they're on, the rocks will go back to their original configuration, allowing the party to proceed west and down once again to the Lower Cavern.
The lava is now cooled down here, allowing you to walk on the floor safely. The chest on the middle platform contains a Ribbon, another of the few Treasures the treasure hunter couldn't obtain. The path back to the Upper Cavern is in the northwest corner of the area. Follow the obscured path south, then hop across the path party 1's switch is creating to rejoin your allies. If party 2 is going to confront the Red Dragon, they can do so now. Otherwise, have each party stand on one of the southern switches. Doing so unblocks the path to the south.
Either party can proceed along the path to the Lower Cavern. You'll find Locke on the central platform, and as you approach him, he will show you the Phoenix Esper. You'll automatically be transported to Kohlingen. (If you return to the Phoenix Cave, the shining light in this room serves as an exit.
In Kohlingen, a series of cutscenes will play out. At the end of them, Locke joins with the Phoenix Esper and he gives you the contents of the empty chests you ran across: an X-Potion, a Fenix Down, an X-Ether, an Elixir, a Flame Shld, and the ValiantKnife. You'll be in a party consisting of only Celes and Locke. Note that you'll need someone to learn Life 3 from Phoenix before you can safely complete the Tower of Fanatics.
Locke in Narshe
Getting Locke and Phoenix is great, but you haven't obtained all of the prizes of completing the Phoenix Cave just yet. There are five locked houses in Narshe that only Locke can unlock. Three of them (the Inn, Relic Shop, and Item Shop) are completely empty, but the other two contain some of the most valuable Treasures in the game. In the Back Room of the Weapon Shop, the shopkeeper has the Ragnarok Esper, which he offers to forge into a sword. You can choose the Esper, which teaches Ultima (the undisputed best Spell in the game) and turns Monsters into Items when summoned, or the Ragnarok sword, a powerful weapon that can be wagered at the Colosseum for the even more spectacular Illumina.
Note that Gogo cannot uncurse the Cursed Shld.
The other locked building of interest is the House behind the Relic Shop. A man in bed there will give you the Cursed Shld, an unequivocally awful piece of Armor with one saving grace: if you equip it for 256 battles, it becomes the ridiculously broken Paladin Shld. This shield is the only way to learn Ultima without the Ragnarok Esper, so you'll definitely want to uncurse the Cursed Shld if you chose the Ragnarok sword. Just make sure you're always using a Ribbon with the Cursed Shld.
The Illumina
If you chose the Ragnarok sword, you can wager it at the Colosseum for the Illumina. The Illumina is superior to the Ragnarok in many respects—it never misses, deals full damage from the back row, and offers an extra 20 MBlock% and +4 Speed—but the Ragnarok does have one advantage. It randomly casts Flare when you attack with it, which is non-elemental and ignores Mag.Def. The Illumina instead casts Pearl, which is subject to Mag.Def and which some monsters ignore or even absorb. On balance, the Illumina is clearly the superior Weapon, but it is worth being aware of what you're trading the Ragnarok for.
If you wager the Ragnarok, you'll fight a Didalos, a Monster that normally appears in Kefka's Tower. It has 12,280 HP and can cast Flare for over 2,000 damage, so it won't be an easy fight. Protection from Fire and Wound are vital, and a Wall Ring will prevent Flare from hitting you and cause it to hurt the Didalos instead. It is still possible to lose due to the randomness inherent in the Colosseum, but you should have a good chance with the proper preparation. Worst case scenario, reload and try again!