Tried out a new team today in the Battle Maison, the only other three IV bred, EV trained Pokemon I have, Magic Bounce Espeon / Gooey Goodra / (Mega) Blaziken. They are good Pokemon separately, but together they don't work that well together. Sadly that streak ended at 21, thanks to a Pure Power Medicham that even after being burnt blasted through all three of them.
In my experience, having two sweepers and one Pokemon that can tank hits and spread status is the formula for success, I've found my Rotom-H / Rotom-W (I change it depending on the other members) to be extremely helpful, spreading burns and paralysis, while also having great bulk.
Medicham is ridiculous...it ended my streak twice. I'm gonna have to breed for a Timid Gengar now
White Kyurem, the dragon infused with the power of Reshiram