Riku's packing a team of level 100s, so he already has power on his side. Fortunately, he has a solid amount of type coverage and spread attacks, as he really does just wanna get this over and done ASAP.

He'll probably just lead with Flare and have him mega evolve into Charizard X and use a ton of brute force and Earthquake to muscle his way through the trainers. Sorry, Aether, guys! He doesn't have time to play soft.