Alder is the Champion of Unova, and the last to beat before entering the Hall of Fame. He is waiting for you at the top of the stairs once you talk to the statue, which will take you downstairs. He says that he’s finally been waiting to determine the strongest Trainer of the Unova region, and the battle begins. This is your first battle with him, if you’ve just beaten the game. Because N interrupted with the Team Plasma affair, you didn’t have time to battle him and become the Champion. Now, you’ll see that his team is completely balanced with no specialty in any type whatsoever.
His first Pokemon is Accelgor, which is extremely fast. It can use Me First, so make sure you don’t use a move supereffective to your own type. Other than that, it utilizes Bug Buzz, Energy Ball, and Focus Blast, all of which are threats. I prefer to use Rock Slide, but if you can’t beat it in Speed, wait for an attack to miss. That’s when you can gain the upper hand.
Alder’s second Pokemon is Bouffalant, the Normal-type. Grass-types are a bad idea, since it has Sap Sipper and won’t take any damage from those kinds of attacks. It uses powerful moves, even though it’s slow; its defensive ability is above average and won’t be taken out easily. Most of the time, it will use the recoil move Head Charge, which could help by gradually chipping away at its HP.
Next is Druddigon, which is a pure Dragon-type, despite its wings. Its only strategy is to use Outrage; prepare yourself by using physical defenders. Then, try to use special moves, since it has Rough Skin, and damages physical attackers. It’s weak to Ice-based moves; I always use Ice Beam to take it out in one hit.
Alder’s fourth Pokemon is Escavalier, which is slow, but has tons of Defense. The good news is that it is weak to Fire-types, many of which are special. If you didn’t bring any, try using a Ground-type, since none of its moves are supereffective against them. Ground-type moves will do regular damage, but at least you can take it out in a few turns.
Usually, Alder saves Volcarona for last, but in my recent battles with him, he always sends it out fifth. Anyway, its double weakness is Rock, so using Rock-based moves is a great idea. However, it likes to use Quiver Dance, which raises Special Attack, Special Defense, and Speed. This is followed by either Bug Buzz, Hyper Beam, or Overheat. It’s a huge threat once it’s buffed with a few Quiver Dances, so resort to physical attacks, where it’s the weakest.
Finally, you will face Alder’s defensive Pokemon, Vanilluxe. It only knows Blizzard and Flash Cannon as offensive moves; I’m sure you can get around its defensive strategy of using Light Screen and Acid Armor. The answer is to use a Fire-type, whose special attacks can burn through its buffer moves. Once you win, Alder congratulates you and takes you to the Hall of Fame, where your Pokemon are solidified as winners. You will see a custcene of them, followed by their nickname (if any) and level. There’s something special for each type, so conquer the Pokemon League with different types to see their effects.