After defeating Marnie & Hop in the Semi-Finals, retrieving Leon from Rose Tower, and defeating Bede one more time, you will finally proceed to the Champion Cup Finals. In order to reach and challenge Leon for The Galar Region Champion, you must defeat three Gym Leaders in a tournament of battles. Your second Finals Opponent in Pokemon Shield will be Allister, who continues to specialize in using Ghost Type Pokemon. In this battle, he will use fix different Pokemon, all of which will fully or part Ghost Types. Because of this, Allister is especially weak against Ghost and Dark Type Pokemon & Attacks.
Additionally, all of Allister's Pokemon will either be at Level 52, Level 53 or Level 54. Due to this, it would be wise to have all of your Pokemon at Level 55 or higher. The more experienced your Pokemon are, the easier it will be to defeat Allister. And finally, Allister will Gigantamax his final Pokemon, which just so happens will be Gengar. Because of this, it would be especially wise to wait to use your Dynamax until he sends out Gengar. Also, it would be smart if the Pokemon you Dynamax is either a Ghost Type, Ground Type, Psychic Type or Dark Type, since Allister's Gengar will be extremely weak to all of those type of attacks.
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