I can't use my DS atm. Well, I can, but not a lot because the DS charger is broken -_-
Sky Ruler... Quick Google search suggests wearing a ring that is resistent to ice (suggestion is the Blizzard charm). Attack when you're close to the tail because it's the only thing you can lock onto. Only use normal attacks because magic is hard to reach it's target. Avoid all the pillars and orbs and when part of the tail is off, just flee until it's stopped it's rampage, then continue until the tail is gone. Next it shoots projectiles, then does a fire attack. Just hide underneath it while that happens and attack it's heart. After the fire attack, it takes a short time to cool off, so attack it then with a bunch of combos and fly away before it attacks with it claws. Repeat until it's done.
I was on
http://kh2.co.uk/ and found out Donald & Goofy are gonna be in the next game

That made me excited, but they don't mention it on the site... It's in one of the scans.