Trick Room and Endeavor are also very important parts of the team. You use Trick Room so your Pokemon go first and Endeavor is used so you can KO Pokemon that can normally survive. Keep in mind that the Togekiss must be Lv2 so Endeavor will reduce the opponent's HP to around 15. With Endeavor, you can have Bronzong use Earthquake to KO the opponent Pokemon. To my knowledge, the Pokemon the CPU are randomly selected from certain sets of Pokemon. There's a trainer that exclusively uses fire and fighting Pokemon. That's probably who you fought that sent out a bunch of fire Pokemon against your team. The team I have in my post is the closest thing I can think of to a team without weaknesses. When used properly, you only lose to very bad luck.