The Onix took the Mud Bomb, and used the Stunfisk as leverage to lift itself up into the air. It then began to fall down towards the Stunfisk.
Meanwhile, Shayd was finishing up his mine cart ride. He was surprised Ken wasn't taking the same route, but was fine with it. He'd be getting to the gym first, and he was fine with that. As soon as he arrived at Under city, though, he heard a lot of havoc. Pokemon Trainers, including the Gym leader, seemed to be fighting a bunch of Pokemon that were going extremely savage, and a group of people were sending out the savage Pokemon. Shayd used his training to sneak up to the platform that the villains were releasing the Pokemon from. Next to them was a Deino.
(koopa mind being the Team Solid grunts?)