It would be quite a tough challenge for me if I ever faced a team that consisted of Bronzong, Machamp, Dusknoir, Gyarados, Cresselia, and perhaps Breloom. Bronzong, of course, would be the lead. It has access Stealth Rock, and thanks to its heavy bulk, it should be able to set these rocks up without worrying about being fainted. Once it gets Stealth Rock set up on the field, my Pokémon would wreck into them as soon as I send them out on the field—causing them to lose about five- to ten-percent of their health every time. Machamp's got access to the No Guard ability, which would allow it to hit DynamicPunch, one of the most powerful fighting-type attacks, at hundred-percent accuracy. It'd never miss. With DynamicPunch, Machamp would be able to take out quite a few of my Pokémon. Dusknoir would be one of the team's walls, and stall me for as many turns as possible. Gyarados would be the physical sweeper of the team, and Cresselia would be the special sweeper. As for Breloom… that Pokémon would be a physical sweeper, too, I guess. xD It's got Spore in its arsenal, which would enable it to make any of my Pokémon fall asleep in an instant. While they're asleep, Breloom would be able to set up Swords Dance and start to wreak havoc with Mach Punch and Seed Bomb.
This would be a very solid team all-around, and it'd be nearly impossible for anyone to have it taken down—not just me.