This gym specializes on Fighting-type Pokémon. Using Psychic, Fairy and Flying-type moves are recommended. A warning for those using Flying-type Pokémon: A lot of the Pokémon in this Gym can use Rock-type moves. If you will use a Flying-type Pokémon, make sure it can take a hit if it cannot defeat its opponent in one turn.
The gym’s gimmick would be the use of Roller Skates. There will be skaters strolling around the track and they will challenge you as soon as they encounter you. You need to defeat four trainers in order to get to the middle.
Roller Skater Kate(Prize Money: P896)
Roller Skater Shun(Prize Money: P864)
Roller Skater Dash(Prize Money: P960)
Roller Skater Rolanda(Prize Money: P928)
When all platforms are raised, skate on the bar to the middle area to reach the Gym Leader
Leader Korrina(Prize Money: P5,120)
After defeating her, you will receive the Rumble Badge. This will allow you to use the HM Surf outside of battle. It will also make Pokémon up to LV50 obey you even if they are traded. She will also give you TM98 Power-up Punch.
She will also tell you that in order to obtain the Mega Ring, you would have to climb the Tower of Mastery and battle her again.
Leave via the bar to the south and exit the gym then head for the Tower of Mastery.