From Bulbapedia, the community-driven Pokémon encyclopedia.
It's been many days after Team A.C.T. went down to fight Groudon, and the people of Pokémon Square start to worry, so a town meeting is called. Blastoise, Octillery, and Golem agree to go down and save Team A.C.T. Here you might want to do optonal missions in places where high level Pokémon are because you're about to go down there as well. Level up to about Lvl 25 - to Lvl 30 because this is going to be a rough dungeon. Anyway, after a day or two, the rescue party comes back wiped out. After an inspiring speech your partner gives, rescue teams of all sorts gather their pride and march down into Magma Cavern.
This is the largest dungeon yet. After 23 levels of pure terror, a save statue awaits you.
Then there are another 2 floors.
You will come upon Tyrannitar and Charizard who say Alakazam is still fighting. You go up to Alakazam and with a flash of light he is gone but out comes Groudon, the continent Pokémon. Now comes a tough fight; just use the previous boss strategies and you should be able to pull out a win.
You return from Magma Cavern a hero, but don't relax yet. Xatu has seen a new peril, a falling meteor. The only way to stop it is to convince Rayquaza to help, and your team is up to the task.
To get here you will need the 'Teleport Gem' from Xatu. To get it, go to the dungeons list, click Sky Tower, and you'll meet Xatu at the peak of Great Canyon again. You'll use the Gem and be teleported to Sky Tower's 1st Floor. (Why can't they just teleport to the top?) You'll want to be levels 30-35.
This is the final chapter in your storyline. 25 large floors of monsters (some ghosts so watch the walls).
Note: To come back to this dungeon, you need the HM Fly from Wyvern Hill.
Then there will be a save point, and then nine more floors of horror.
At the last floor, you will encounter many Salamence, Metagross, Flygon, Tropius, Claydol, and Aerodactyl.
Rayquaza will be awaiting your arrival on the ninth floor.
Once the mighty Rayquaza is defeated, be prepared for one fantastic ending (but don't be sad, the game will continue on).
- The following items are recommended for these Dungeons:
- Gravelerock (Many)
- Reviver Seed (Many)
- Oran Berry (Minimum, one held by every team member)
- Absol (Partner)
- While fighting Groudon, align your party in such a way that Absol is the ONLY ONE taking damage.
- You may find TM Ice Beam in Sky Tower, this will be 4 x effective on Rayquaza.