Lufenia & the Chime

Two things before Mirage Tower: buy the last two spells in the game and pick up the Chime that opens the tower's entrance. Both require the Rosetta Stone from the Sunken Shrine. Have 80,000 Gil ready for the spells. Level 38-40 is comfortable for this stretch.

Back to Melmond

Fly to Melmond and find Dr. Unne in the northeast part of town, near the gravestones. Show him the Rosetta Stone and he teaches your party the Lufenian language. Without it, every NPC in Lufenia speaks gibberish.

Lufenia

Now that you speak Lufenian, fly to the northeastern continent. Land on the grass patch east of the desert (south of Gaia) and walk south through the forest to reach the hidden city of Lufenia.

The overworld around Lufenia is tougher than the Onrac area. Trolls and Winter Wolves are weak to Fire; Minotaur Zombies burn to Fire and Dia. Everything else has no elemental weakness, so physical attacks are more efficient than spells out here. Hill Gigas and Wyverns appear in the grasslands, while Desert Barettas patrol the sandy stretches between the landing zone and town. Tyrannosaur is the heaviest hitter on this continent, with enough HP to survive several rounds, so focus your party's attacks and don't waste spell charges on it.

Allosaurus is a rare spawn in the forests near town and in the northeast desert. It's easily missed if you don't walk through those tiles. Fight it when it shows up for the bestiary; you won't find it anywhere else in the game. If you're tracking completion through the trophy guide, this is one of the entries people overlook.

Lufenia's people are descendants of a sky civilization that built the Flying Fortress. Talk to them for lore about Tiamat and the Warriors of Light prophecy.

The magic shops are outside the main town walls; take the hidden path in the far east corner (easy to spot on the map). These are the last two spells in the game, both Level 8 at 40,000 Gil each:

• Full-Life (White Magic) - Revives a KO'd ally at full HP instead of the fraction that Life restores. In the final dungeon, bosses hit hard enough to one-shot your squishier party members, so bringing someone back at half HP just means they'll die again next turn. Full-Life solves that problem entirely. Only the White Mage and Red Wizard classes can learn it.
• Flare (Black Magic) - Non-elemental damage that ignores all resistances. Several late-game bosses absorb or resist every element, which makes your other offensive spells useless against them. Flare bypasses all of that. It's your strongest single-target option for those fights, and it'll remain relevant through the final boss.

Buy both. You should already have Holy and NulAll from Gaia; if you left a Level 8 slot open as recommended, these fill them perfectly.

The Chime

Head to the southwest corner of town and find the Lufenian standing on the eastern dock. He recognizes your party as the Warriors of Light and gives you the Chime, which opens the sealed entrance to Mirage Tower.

Before you leave, make sure your gear is in order. Check the weapons page to confirm you're carrying the best options available at this point; if you missed the Light Axe or Defender from earlier chapters, consider going back for them. Stock up on at least 50 Potions and 30 Ethers, plus a handful of Gold Needles and Phoenix Downs. Mirage Tower connects directly into the Flying Fortress with no way to leave in between, so anything you forget stays forgotten until you clear both.

Board your Airship and fly to the tip of grass west of Lufenia, south of the desert. And make sure every caster has full spell charges before you step inside. The next two areas are a marathon, not a sprint.