I'd be more on the lines of this.....I would be a gym leader that specializes in more then one type. I already have a full team of 6 for all 18 types in ORAS. So pretty much,my gimmicks would be that I never use the same Type twice in a row. So if you loose to me the 1st time...you'd be facing a different type.
Dragon- Noivern, Hydreigon, Haxorus, Garchomp, Tyrantrum, Mega Charizard X
Dark- Bisharp, Pangoro, Hydreigon, Greninja, Umbreon, Mega Houndoom
Bug- Galvantula, Volcarona, Armaldo, Scizor, Vespiquen, Mega Beedrill
Steel- Scizor, Aggron, Lucario, Excadrill, Empoleon, Mega Mawile
Water- Vaporeon, Tentacruel, Lantern, Kindra, Carracosta, Mega Gyrados
Fire- Delphox, Infernape, Ninetails, Houndoom, Chandalure, Mega Charizard Y
Ice- Froslass, Weavile, Aurorus, Lapras, Glaceon, Mega Abamasnow
Rock- Kabutops, Rhyperior, Macargo, Gigalith, Archeops, Mega Tyranitar
Fighting- Hitmonchan,Hawlucha, Toxicroak, Gallade, Chesnaught, Mega Lopunny
Electric- Galvantula, Magneton, Jolteon, Heliolisk, Wash Rotom, Mega Ampharos
Fairy- Gardivoir, Azumarill, Sylveon, Whimsicott, Wilgglytuff, Mega Alteria
Grass- Chesnaught, Mow Rotom, Trevnent, Leafeon, Roserade, Mega Sceptile
Ground- Steelix, Nidoking, Torterra, Koorkodile, Golurk, Mega Garchomp
Ghost- Shedinja, Chandalure, Mismagius, Agislash,Sableye, Mega Gengar
Poison- Ariados, Nidoqueen, Seviper, Crobat, Dragalge, Mega Venusaur
Psychic- Delphox, Gardivoir, Malamar, Starmie, Espeon, Mega Metagross
Normal- Girafarig, Pyroar, Heliolisk, Sawsbuck, Staraptor, Mega Kangeskhan
Another gimmick would be that my rules would be different depending on how many badges you have.
If you can adapt and overcome my gym. Not only do you earn the "Adaption Badge"...You are ready for the Pokémon League! So go out and show that you earned this one.