Spirit Palace
Written by MSG Commander
When you enter the last screen of the Spirit Palace, there are still some monsters in here - and this time, you do get to fight them.
Boss Battle

Heaven's Gift x2
5358EXP/90SP/11648G
Drop: Wholesome Ring B (x2)
At the start of the battle, they'll most likely use Field Boost, which raises everyone's stats 1 rank - including their own - so by itself it doesn't seem to do much. However, if you lower their stats 1 rank, it will give you a bit of an advantage.
Whether you lower the enemy's stats or not, just use your favorite skills, magic or unisons, and watch everyone's HP.
Heaven's Gift is Light-based, so Shadow magic would be effective in this battle.
Whatever strategy you use, these enemies are really not that hard. (About the worst thing they did to me was to put two party members to sleep.)
After the battle, Viniera says she thinks a black amaryllis may be somewhere in Estrella. She says you should try looking in the south side of Deneb Peak - which apparently, you can't reach by land, because then she tells Aither to prepare the Dirigimoo, which is some sort of flying Moomie.
After the dialogue, exit the Spirt Palace and Nebulus Village, and skip talking to Aither (apparently there's a bug in the game, that makes it impossible to talk to her.) Just walk on to the flying Moomie, and press "Ride."
Note: the Dirigimoo can't fly over mountains, so you need to fly around the mountains to the east of Nebulus Village, until you find the south entrance to Deneb Peak.
Treasure
VIT Seed x5 - west side of the first screen
Pumpkin Patch Kid +6 (Rage 15 HP 20) - center of first screen
Maintenance Ring - east side of first screen
MP-less Ring - secret passage on the second screen
Acceleration Ring - secret passage on the second screen