H-here I go...
Rave Badge
>DJ-themed Trainer
>Exploud
>Spinda
>Magnezone
>Porygon-Z
>Scrafty
>Electivire
The gym would have an undergound party theme, with a lot people roaming around because the gym leader hosts parties every night, the leader is on the stage and you have to find your way through the crowd. Inside the crowd would be trainers that would challenge you, as well as some people who would give you various drinks (i.e. Lemonade, Soda etc.) and berries either because they're drunk from all the craze or that they're just friendly, and random items that you could find. Sometimes you would also encounter groups of various teams from the 5 regions, defeating 2 to 3 grunts of the same team will cause grunts of their teams to leave, thus making your way to the leader faster. The gym also has its own background music, and its beat gets faster and faster after every battle you face causing some of your pokemon to get confused during battles. Once you are battling the leader, you will notice that the battle music has changed into a techno-themed song that gets faster and faster after every faint. Once you have defeated him he will give you the Rave Badge and also will teach one of your pokemon Uproar.