This is a guide to the final instance in Celestia, the Test of the Spheres.
When you enter, there will be three puzzles to solve.
FLOOR 1 (Star)
Test of Constellation: Use each of the stands once to align the stars, completing this puzzle.
Test of the Shining Stars: Four lights are in a + formation. Use them in the order of: Bottom, Left, Top, Right, lighting them all to complete the puzzle.
Test of Vision: Turn all four heads to face the bowl to complete this puzzle.
1: Astraeus
Rank 11 Boss
Astral
7210 health
Starts with 6 power pips
On the first or second turn, he will say "The Constellations Form Again!", put up a 90% tower shield, and call three minions. The 90% tower cannot be removed until all the minions are defeated, except by using Pierce or Steal Ward. The minions will only use attacks such as 1-pip Natural Attack, Leprechaun, Troll and Fire Elf, but they will frequently Sprite the boss. When they are all dead, the tower shield can be removed. This cycle repeats every few turns, making for a very long battle.
Observed Spells
Tower Shield
Amplify
Fortify
Power Nova
Judgement
Elemental Blade
Elemental Trap
FLOOR 2 (Moon) (Puzzle too big to take a picture)
Puzzle: Use each of the stands until it locks up to align the moon holograms. Then, battle each of the four sets of minions. When each set is defeated, they will leave behind a silver chest. Get a Moon Shield from each one and give them to the statues near Ptolemos. This will open the boss's door, completing the puzzle.
2: Ptolemos
Rank 11 Boss
Lunar
7320 health
Starts with 6 power pips
On the first turn, he will put up a 90% tower shield. It cannot be removed, however, if you or a teammate use a blade or Guiding Light, he will say "You Have Charmed Your Way Into My Heart!" and he will remove any and all shields on him, excluding stun shields. When someone attacks and does not have any blades left on after the attack, he will say "Your Charm Has Worn Thin!" and replace the shield after the attack.
Observed Spells
Colossus
Frostbite
Frost Giant
Natural Attack (Storm, 125 per pip)
Tower Shield
Moon Blade (+35% to next Death, Myth and Ice spells)
Moon Shield (-50% to next Death, Myth and Ice spells)
Wraith
Scarecrow
Elemental Shield
FLOOR 3 (Sun puzzle)(Puzzle too big to take a picture)
Puzzle: There are four mirrors around the room. Each one produces a gold chest when used. Get the swords from the chests and give them to the statues to complete this puzzle and unlock the teleporter to the final boss.
FLOOR 4 (Sun boss)
3: Mithraya
Solar
Rank 11 Boss
7100 health
Starts with 6 power pips
Whenever someone uses a spell successfully, she will interrupt after their turn and place a Smoke Mantle on them. Sometimes, after everyone has taken their turn, she will interrupt and use Smokescreen. She will only stop her mantling/screening when your blades and traps are set, under which conditions she will say "The Cards Align! Now's Your Chance!"
Observed Spells
Smokescreen
Smoke Mantle
Natural Attack (100 damage per pip, Fire)
Kraken
Triton
Wild Bolt
Darkwind
Sun Shield (-50% to next Life, Fire and Storm spells)
Sun Blade (+35% to next Life, Fire and Storm spells)
Guiding Light
Regenerate
This didn't seem to fit in well in any other section, but here are the observed spells of Stellar Protectors:
Amplify
Fortify
Smoke Mantle
Smokescreen
Phoenix
Helephant
Elemental Blade
Elemental Trap
Congratulations! You have beaten Celestia, and, if this is your first time through, earned 25,000 experience! (If your second time, 12,500.)
SPECIAL THANKS TO:
Johnny for offering his pics even though I didn't use them
Myth Princess for informing me Mithraya could bolt
Everyone else who helped with the guide
Everyone who liked the guide :D
And Kingsisle obviously :P
For information on what these bosses drop, visit Deathshard's excellent guide here.