Frost said:People are really underrating the potency of Drought in making Mega Charizard usable. Drizzle and Drought singlehandedly brought Ninetales and Politoed to OU in Gen V, guys. It doesn't matter if Mega Charizard has a 4x Rock weakness; unless they severely nerf the weather, it's still an incredible ability that will make Mega Charizard see use.
In weather wars, the weather setter has to be able to switch in and out of battle. Charizard is one of those Pokemon that has to stay in.
This is a common weather scenario:
P1 sends out drought ninetales
P2 sends out hippowdon, since hippo is slower, his weather is dominant.
P1 switches
P2 sets stealth rock
Both ninetales and charizard are too fast against opposing weather teams. Difference is it takes 4 stealth rocks to take out ninetales but charizard goes out with 2. At least with Blaze he can benefit from stealth rock weakness.
Now, going up against non-weather teams, he'd make for a worry-some threat