Been playing Black 2 for fun, bored of it now but got to 63 without losing:
Ferrothorn @ Leftovers
Iron barbs
252 hp, 252 sp def
Impish (+def, -sp atk)
Protect, Leech Seed, Toxic, Flash
Chandelure @ Choice Scarf
Flash Fire
252 sp atk, 252 speed
Modest (+sp atk, -atk)
Overheat, Shadow Ball...