After you reveal Dhaos's hiding place, you can search for Ayflite's legendary treasures.
Go to the Freezekill pub. Talk to the man at the far left and say Yes. Afterward, you can talk to him again to hear where all of the treasures are hidden.
From Freezekill, fly south and slightly west to some sandy/grassy areas. Land on the section with the smaller spot of grass. Walk down. The chests, from left to right, contain Whale Meat, a Mental Ring, and a Hyper Gauntlet.
Now fly north and slightly west until you are over Ary, which is the city on the island that is always dark. West and slightly south of the city is an island that consists mostly of mountains, and some grass. Land on the grassy part. The chest on the left contains Whale Meat and the one on the right contains a Resist Ring.
Fly over the cave that takes you to Dhaos's castle, and fly north. Land on the grassy strip of land. The chests are at the upper right of the screen. The upper chest contains a Blue Candle, and the lower chest contains Sefira.
Fly northwest until you are over Morrison's house, then head west. Land on the strip of sand blocked by the mountain. The chests, from top to bottom, left to right, contain Whale Meat, the Blue Line Shield, Black Onyx, Green Torch, Armlet, and Elixir.
Fly over the Spirit Forest, and go southeast to an area of sand blocked by mountains. The treasure here is a Reverse Doll.
Fly over Gnome's Cave and look northeast to see an island with a mountain, some sand, and some grass. Land on the grass. There are three chests hidden under the trees in the center. From left to right, they contain a Dark Seal, Elixir, and Mental Ring.
On the same island as Treasure 6, land on the small sandy area on the east side of this same island. After you land, walk south. The chests are in the water. The one on the left contains Whale Meat, and the one on the right contains a Protect Ring.
Fly northwest, over Bart's old house, and look northeast. Land on the area of sand surrounded by mountains. You will find a Silver Cape.
Fly northest from Treasure 8 to where Harmel used to be, across the bridge north of the Long Valley. If you turn to face west and a little north from here, you will see an island with a mountain on it. Land on the sand. If you don't automatically end up in a new area, walk around until you do. The treasure on the left is Whale Meat, and the treasure on the right is a Moon Crystal.
From Treasure 9, fly northeast. Land on the small area of sand on the edge of the continent surrounded by mountains. The chest on the left contains Whale Meat and the chest on the right contains a Reverse Doll.
Fly southeast, over Alvanista. Go south and slightly east to a long sandy island. You will find a Silver Mattock.
Fly over Alvanista. Go north and slightly east, and you will see a stretch of land reaching into the ocean, with a small island at the end. Land there. From left to right, the chests contain Whale Meat, a Silver Cape, and a Resist Ring.
Fly east, over the Tower of the Twelve Stars, and fly west. There will be several sections of land beyond the mountains. Land on the one with forest. There is a chest hidden in a little crevice in the trees on the left side of the screen. It contains a ?Weapon that becomes a Tidal Axe.
Fly southeast over Freland, over the northernmost oasis, and to the east you will see an island with a mountain on it and some sand. Land on the sand just south of the mountain. From left to right, the chests contain Whale Meat, Elixir, Drum Set, Elixir.
From Treasure 14, fly west, and you will see a long island with mountains on it. Land on the sand. From left to right, the chests contain Whale Meat, Jade Ring, Soup Pot.
Fly north, over where Midgard was. Fly southeast until you come to an area of sand and mountains reaching out into the ocean. Land on the farthest sandy patch. There are 9 chests here, all containing Sake.
Fly over the White Forest. Fly north and land on the beach. In the water, from left to right, the chests contain Elixir, Gold Helm, S-Flag.
From here, fly east and land on the snow in the mountains. There are four chests here, hidden under the trees. From left to right, they contain, Namco Gamer, ?Weapon = Lucky Blade, Elven Boots, Jade Ring.
Fly over the bridge that led to Dhaos's Fortress northeast of the Valhalla Plains. To the south is an area of beach that is totally enclosed on both sides by mountains. Land there. From top to bottom, left to right, the chests contain Red Line Shield, ?Weapon = Duellist's Sword, Elixir, Red Lantern, Elven Boots, Cat's Eye.
Fly over where Dhaos's Fortress used to be. Look northwest and you will see a small island with two sandy areas. Land on the bigger sandy area. The chests contain Whale Meat.
From Treasure 20, fly northeast, over Ymir. Go southeast and land on the sandy area pointing out to sea. The treasure is behind a rocky outcropping. It contains a Protect Ring.
Fly over Ymir again, and fly east this time. Land on the tiny, round, sandy island to find Rosa's Dress.
Go to the Freezekill Pub and talk to the man who told you about the treasure. You will give him Rosa's Dress.
About the Treasures
The Whale Meat cannot be put into the food sack. It is just a trading good. Check different shops to find out how much they will pay for it, then sell it to whoever offers the most gold.
The Namco Gamer is Klarth/Claus's best weapon.
Equip Cless/Cress with the Blue Line Shield, the Gold Helm, and the Hyper Gauntlets.
The Lucky Blade is not as strong as the Eternal Sword, but it raises your luck as you go up in level.
The Dark Seal is an item that can be equipped on Cless/Cress to increase his received EXP by 50%, but prevents him from using skills. You can use a Rune Bottle on it to permanently turn it into a Demon Seal for Cless/Cress, which increases his received EXP by 200%, but drops his defense to 0 and prevents him from using skills.
Use a Rune Bottle on the Sefira to turn it into Sefira+1. Just by having it in your inventory, you will earn 20% more EXP and gold from battles.