In Order to get all these weapons, you first have to get the Celestial Mirror. Go to Belgemiene's Castle, by using a chocobo in the Calm Lands in the southeast corner, jump by touching the yellow feather. Go around the side of the castle to find a chocobo. Race down to the finish line on the chocobo(very easy, I did it on my first try) to recieve the cloudy mirror. Go to Macalania forest. Go backwards into the forest from that icy place where you fought the Al Bhed cannon. Go to the right(your right) and enter an area with two guado women, and another guy. Talk to the guy until he says about meeting his family. Tell him you saw them over there. The guy will leave. Find him again in the central part of Macalania (there's a Jecht sphere there) and talk to the guy and his wife. They'll say their kid got lost. Go to the sparkling trail on the left and go up. You'll find the kidin front of one of those big plant things. Then walk up to the plant once the people left, and the cloudy mirror will become the celestial mirror.
Tidus-Caladbolg
To get this sword, beat the chocobo trainer at all 4 events. Go to the north-west corner of the Calm Lands where the guy was standing before. go down and use the Celestial mirror to recieve the Caladbolg.
Tidus's Crest-Go to the room where you fought Yunalesca to get in from a chest.
Tidus's Sigil-A very annoying task indeed. You have to beat the chocobo trainer in a race and achieve a time of 0:0. To do this, you must dodge all birds, and get 15 balloons, or get more than 15 to compensate for each bird you hit. This usually takes me quite a few hours to do, and it is very frustrating.
Yuna-Nirvana
After you capture all the creatures in the Calm Lands for the old arena guy, He'll give you a chest you have to open with the Celestial Mirror.
Yuna's Crest-Go to Besaid and swim along the coast up stream until you find an inlet of land. The Crest is in a chest there.
Yuna's Sigil-Defeat all 8 of Belgemiena's Aeons at Remiem Temple.(you have to get Anime, Yojimbo, and the Magus sisters before you can fight all 8)
Auron-Masamune
Instead of going in the cave where you find Yojimbo, tak the path to the right until you find the rusty sword. Take it back to D'jose/mushroom rock and find an elevator platform. Go up and insert the rusty sword in a small nook. The Masamune will then be yours.
Auron's crest-On the Mi'ihen highroad, you'll need a chocobo to get to it.
Auron's sigil-Catch all the monsters from ten different areas, the arena guy will give you the sigil as a reward
Kimahri-Spirit Lance
On the Thunder Plains, you'll find glowing Cactuar stones. Pray to three of them using the square button. Then, go back close to the beginning of the Thunder Plains and find the ghostly Cactuar(he's kinda hard to see) and find a burnt down lightning tower. Pray to it with the square button again and a treasure chest will appear. Use the Celestial Mirror to open the chest.
Kimahri's Crest-examine the pillars on Mt. Gagazet just beyond where you fought Seymore. It's in a chest on te left.
Kimahri's Sigil-Win the butterfly catching game at Macalania forest.
Lulu-Onion Night
Go to Baaj Temple(coordinates X-16 Y-57 in the airship) and jump in the water. Search around in that main area. When the camera zooms in, examine the wall to find the Onion Night.
Lulu's Crest-In a chest at the Farplane in Guadosalam
Lulu's Sigil-If there's a sigil you won't get, it'll be this one. Getting it is a horrifying quest. Go to the Thunder Plains and dodge 200 CONSECUTIVE lightning bolts. Then go to the inn and check the chest outside. But if you get hit once, you're done.
Wakka-World Champion
After winning about 5 games of Blitzball, the bar tender at Luca will give you this.
Wakka's Crest-In the Besaid Aurochs locker room in Luca.
Wakka's Sigil-After getting all four of Wakka's overdrives, it'll become available as a Blitzball prize
Rikku-Godhand
In the "input" menu on the airship, enter "GODHAND"(make sure it's all capitals), then go to the area it opens. You'll find the Godhand in a chest there.
Rikku's Crest-In the northwest corner of the fourth section of the Sanubia desert.
Rikku's Sigil-Play the Cactuar mini-game at Bikanel island. find the Cactuar monument in the fourth area, and it'll say about 10 gatekeepers. You must find each one, beat it, then return with it's sphere. Here are the locations:
1. Tomay-At the first area, where Tidus washed up on shore.
2. Rovivea-Northwest area of the second desert section.
3. Chava-Behind the Al Bhed 20% off sign in the fourth area(the second sign directly left from the Cactuar monument).
4 & 5. Alek and Aloja-Running around in the ruins to the west in the third desert area.
6. Vachella-Behind the save sphere in the second area(touch the sphere for it to appear).
7. Robeya-In a treasure chest to the southwest in the third area.
8. Issra-in an antlion pit in the fourth area. You have to leave the area and come back.
9. Elio-At the very beginning, where Tomay was, but he warps onto your airship. Go out onto the roof to get him.
10. Flaile-He appears behind the monument when you get the other 9 Cactuars.