You'll have to be running a max HP, max attack Charizard, n you should not mega evolve on the roar of time. Then you take a roar of time and then you can dragon dance up, n the turn he recharges you can use another DD n use flare blitz/outrage to clean dialga up. This is like the only way.
(U could also use flare blitz/outrage twice after a dragon dance but same result)
And your opponent should not used rock slide on his first turn.
Flare blitz and outrage are superior to EQ because they get boosted by tough claws and they get STAB