FFX - Sidequests - Celestial WeaponsEach character has an "ultimate weapon" that he or she can acquire. However, to really use these weapons, they need to be "unlocked" first. So each character needs three items: the weapon itself, and its Crest and Sigil. Note that this sidequest can only be done after you obtain the airship.
Cloudy Mirror/Celestial MirrorFirst you must get the Celestial Mirror, or you can't do anything else. This will allow you to open the chests containing the weapons, and to charge them up.
Go to Remiem Temple. To get there, head to the Calm Lands, and get a chocobo from the chocobo trainer. She's usually near wherever you've entered the Calm Lands. Ride it to the entrance to Macalania Woods, and at the edge of the small cliff you should see a broken bridge, and a feather on the ground. Press [x] near the feather, and the chocobo will fly across to the platform. This is Remiem Temple. Talk to the chocobo on the right to race the one on the left. Win the race to recieve the Cloudy Mirror. (Note: you can get other things here as well; see the Remiem Temple section).
Head back to Macalania Woods, and talk to the mother standing near the entrance. Then go speak to the father at the campsite. Return to the entrance and speak with the mother and father a few times each, until they mention their missing son. Then go up the sparkly path to the left of the main one, and you'll find the son if you go up at the first fork. Talk to the crystal-looking thing, and it will turn the Cloudy Mirror into the Celestial Mirror. Now comes the fun part.
Tidus [Caladbolg]Weapon Location: Northwest corner of the Calm Lands, down a narrow path. Win all four chocobo races, and the person blocking the path will leave.
Sun Crest: Zanarkand Dome, on a staircase in the area where you fought Yunalesca.
Sun Sigil: Win the fourth chocobo race with a time less than 0:0:0.
Yuna [Nirvana]Weapon Location: In a chest in the Monster Arena. You must collect at least one of each monster in the Calm Lands.
Moon Crest: Besaid Island, on a beach in a cove on the east side that you must swim to.
Moon Sigil: Defeat all of Belgemine's Aeons at Remiem Temple, including Yojimbo, Anima, and the Magus Sisters, and then send her and you will recieve it.
Wakka [World Champion]Weapon Location: The bartender in the Luca Cafe will give it to you if you've won at least 5 Blitzball games.
Jupiter Crest: In a locker in the Auroch's locker room in Luca.
Jupiter Sigil: Random grand prize in the Blitzball league game, after winning all of Wakka's Overdrives.
Lulu [Onion Knight]Weapon Location: In the pool at Baaj Temple, opposite the doorway to Anima's shrine. It's very hard to see, but the camera switches angles when you come near it, so swim around until that happens and keep pushing [x].
Venus Crest: In a chest at the Farplane in Guadosalam.
Venus Sigil: Dodge 200 lightning bolts consecutively at the Thunder Plains; it will be in the chest outside the travel agency.
Kimahri [Spirit Lance]Weapon Location: Pray at 3 of the glowing cactuar stones in the Thunder Plains by pressing [square]. Return to the south part, and you will see a cactuar ghost - follow it to the tower, where you must pray again to find the chest.
Saturn Crest: Mt. Gagazet, in a chest among the pillars just past the area where you fight Seymour.
Saturn Sigil: Win both of the butterfly catching games in Macalania Woods.
Auron [Masamune]Weapon Location: In the Calm Lands valley, down the road opposite the Cavern of the Stolen Fayth, grab the Rusty Sword. Then head to Mushroom Rock Road, and keep going north, until you see a green square on the left representing one of those floating mushroom elevator type things. Stick the sword in the ground next to the statue to recieve the Masamune.
Mars Crest: Mi'ihen Highroad, Oldroad. At the entrace to Mushroom Rock Road, hang a U-turn to enter the Oldroad.
Mars Sigil: Unlock 10 Area or Species Creations at the monster arena (capture 10 of each monster from an area or a species), and the trainer will give it to you.
Rikku [God Hand]Weapon Location: In a chest on Mushroom Rock Road. Input the airship password GODHAND in order to go there.
Mercury Crest: Treasure chest in the fourth screen in Sanubia Desert.
Mercury Sigil: Treasure chest in the Sanubia Desert, behind the sandstorm. Complete the Village of the Cactuars sidequest first.