Here's how it goes...
CLOUDY MIRROR
- The surface is dark and clouded.
- Win a chocobo race at Remiem Temple.
- Needed to gain Celestial Mirror.
-------------------------------------------------- -------------------------- CELESTIAL MIRROR
- The surface is shiny and bright.
- Obtain by powering up Cloudy Mirror at the great sphere in Macalania Woods.
- Needed to obtain Celestial Weapons.
--------------------------------------- SUN CREST
- A Celestial Token, fashioned in the shape of Sun.
- Obtained after defeating Y. Woman.
- Needed to power up Tidus' celestial weapon.
-------------------------------------------------- -------------------------- SUN SIGIL
- A Celestial Token, fashioned in the shape of Sun.
- Obtained after getting time faster than 0.0.0 at chocobo race in Calm Lands.
- Needed to power up Tidus' celestial weapon.
-------------------------------------------------- -------------------------- MOON CREST
- A Celestial Token, fashioned in the shape of Moon.
- Found on Besaid's beach near where you met Wakka for first time.
- Needed to power up Yuna's celestial weapon.
-------------------------------------------------- -------------------------- MOON SIGIL
- A Celestial Token, fashioned in the shape of Moon.
- Obtained after defeating all of Belgemine's aeons and 'dismissing' her.
- Needed to power up Yuna's celestial weapon.
-------------------------------------------------- -------------------------- MARS CREST
- A Celestial Token, fashioned in the shape of Mars.
- Go to the place where S. convinced few guards to let you thru barricade. There's a path leading down and right. Enter it and you'll be on Oldroad. Go all the way to the end and you'll find Mars Crest in the chest.
- Needed to power up Auron's celestial weapon.
-------------------------------------------------- -------------------------- MARS SIGIL
- A Celestial Token, fashioned in the shape of Mars.
- Unlock combined total of 10 Area and/or Species creations.
- Needed to power up Auron's celestial weapon.
-------------------------------------------------- -------------------------- SATURN CREST
- A Celestial Token, fashioned in the shape of Saturn.
- Found on same screen where you fought Flux. There's a bunch of pillars. Between third and fourth on the left is a chest with this item.
- Needed to power up Kimahri's celestial weapon.
-------------------------------------------------- -------------------------- SATURN SIGIL
- A Celestial Token, fashioned in the shape of Saturn.
- Complete both butterfly games in Macalania Woods after you get permanent control of the airship.
- Needed to power up Kimahri's celestial weapon.
-------------------------------------------------- -------------------------- JUPITER CREST
- A Celestial Token, fashioned in the shape of Jupiter.
- Found in Auroch's locker room by examining one of the lockers. You
cannot* get it on first visit to Luca.- Needed to power up Wakka's celestial weapon.
-------------------------------------------------- -------------------------- JUPITER SIGIL
- A Celestial Token, fashioned in the shape of Jupiter.
- Once Wakka has appeared in 450 battles against fiends and you have all Overdrives for him, Sigil may appear as a league prize.
- Needed to power up Wakka's celestial weapon.
-------------------------------------------------- -------------------------- VENUS CREST
- A Celestial Token, fashioned in the shape of Venus.
- Found in the Farplane.
- Needed to power up Lulu's celestial weapon.
-------------------------------------------------- -------------------------- VENUS SIGIL
- A Celestial Token, fashioned in the shape of Venus.
- Dodge 200 lightning bolts consecutively. Sigil will then be in the chest in front of Rin's Agency in Thunder Plains.
- Needed to power up Lulu's celestial weapon.
-------------------------------------------------- -------------------------- MERCURY CREST
- A Celestial Token, fashioned in the shape of Mercury.
- Found in western part of Sanubia desert.
- Needed to power up Rikku's celestial weapon.
-------------------------------------------------- -------------------------- MERCURY SIGIL
- A Celestial Token, fashioned in the shape of Mercury.
- Complete Cactuar Village sidequest in Sanubia Desert. Sigil is inside one of the chests in newly accessible part of desert.
- Needed to power up Rikku's celestial weapon.
Hope this helps ;) Have fun!