Driftveil City Pokémon Gym Leader: Clay "The Underground Boss"
Inside Driftveil Gym, there are a number of elevators that are in the mine shaft layout which must be navigated up and down and girders which need to be crossed to reach the central elevator, which will take the player down to Clay at the bottom of the mine shaft. There are several Trainers on the way down.
One of the Trainers in the Gym mentions that the depth of the Driftveil Gym helps to remind Clay that he once started at the bottom with nothing.
In Black 2 and White 2, the Gym no longer features the elevator puzzle, but is instead replaced by a conveyor belt puzzle, that takes to the player to landing platforms. Each time the player lands on a new platform, it lights up. Occasionally there will be viewing platforms, which allow the to see so many platforms from above.
The Driftveil Gym made its debut in The Mighty Accelguard to the Rescue!; however, only the outside of the Gym was shown in this episode due to Clay being too busy to have his Gym battle with Ash.
The inside of the Gym made its debut in Battling the King of the Mines!. Like in the games, the battlefield is located at the bottom of the mine shaft, requiring an elevator for access.
One of the Trainers inside the Gym says that Clay is a company president. It is not known what business Clay actually owns.
Two trainers (Isaac and Felix) share their names with main characters from another Nintendo franchise: Golden Sun. Coincidentally, the characters are associated with the element of Earth.
They don't share their names in other languages, however.