Final Battle With Miror B.
After you defeat Master Greevil and captured all the shadow Pokemon and purifly all of them, go to Gateon Port and the Miror Radar will just go on. Miror B. Will appears at the big lighthouse and you need to bring your best party, because he has 5 Ludicolos and a Shadow Dragonite. Here's Miror B.'s party:
Ludicolo-Lv.57-60
Ludicolo-Lv.57-60
Ludicolo-Lv.57-60
Ludicolo-Lv.57-60
Ludicolo-Lv.57-60
Dragonite-Lv.50 or 60
Note: Have a lot of Ultra Balls, Net Balls, Poke Balls, Timer Balls, Premier Balls, that Luxury Ball from the S.S. Libra, and Great Balls, because Dragonite is a tough one to catch. Just bring Dragonite's HP down to the red zone and use the balls to catch it and then you defeat him.
If you need more help, we've got more Pokemon XD: Gale of Darkness cheats and also check out all of the answers for this game
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