Quoted By:
A Steel type gym, with puzzles based around using magnetic fields to move groups of metal blocks. The fields are generated by different configurations of current-carrying wires. Have fun with that introductory electrostatics, kids!
Alternatively something based around chess puzzles, though maybe that could just be a background motif.
Team would be some combination of the following, adjusting evolution and number of Pokemon for the challenger's number of badges:
Metagross
Magnezone
Aggron
Skarmory
Bisharp
Klinklang
Badge would be the Gauss Badge, and the TM would be Flash Cannon.