Hyden isn't able to make this topic right now so he called me and asked me to. Basically post your challenges here and then I'll tell him about it and he'll then arrange it with you. The badge you'll be battling him for is this:

The battles will be Free Single battles with 3 Pokémon each at fist, but when he has finished all 6 Pokémon, he will battle you with all 6.

There are no rules that are really specific to this Gym, just the basics like the others have, no Ubers and stuff like that.

He is ready for challenges now so post them here and he'll get back to you.