My gym would be a rock-type gym mostly based on stall because that's always fun.
Team
Corsola - light screen, reflect, recover, scald
Omastar (lord helix) - spikes, muddy water, ancient power, toxic spikes
Probopass - sandstorm, volt switch, toxic, flash cannon
Carbink - calm mind, rest, sleep talk, moonblast
Magcargo - stealth rock, recover, lava plume, toxic
Shuckle (the ultimate stall god) - toxic, infestation, rest, shell smash (contrary)