Dragonite was in the lead with this spread:
EVs: 252 Atk / 252 Spe / 4 HP
Moves: Thunderpunch (Pikablu and Togekiss are pains), Dragon Dance, Earthquake, Dragon Claw
Item: Lum Berry.
The other two members were Mega-Kanga with Fake Out/Sucker Punch and Cloyser with Shell Smash and Focus Sash. Didn't really expect anything great from these dudes, but I was only trying to have fun so it didn't matter. 40 Battles into the Super Single Challenge and I thought, "Darn!" this strat really works. Basically, open with Dragonite and get a DD boost. Multiscale and the lum will protect you, so you're almost guaranteed one boost. Then deal as much damage as possible and clean up with one of the other two after 'Nite dies. At least, I thought so until I met some really powerful Ice Pokemon in the first three battles, each one of them in the lead spot.
Pro tip: Icicle Crash KO's through Multiscale.
Anyways, I was sure this was a fail team, but I kept chugging away. After some time (as long as there was no Ice pokes in the lead spot packing Crash ) I realized Dragonite was just as crazy good as ever. When my 41st opponent had a team of Cobalion, Terrakion, and Tornadus and 'Nite destroyed them all (taking a stone edge from Terrakion like a boss) I was convinced, this team was pretty good. I beat the Maison head at battle #50 and got a statue erected in my honor, 50 BP, and a snazzy Trainer Card upgrade.
What experiences have you guys had with the Battle Maison? Any stories, "What the Heck?" moments, or the like? Let me know, and thanks for taking the time to read my rambles!