>>14780838Predict the switch and OHKO it.
Literally the only way.
If they lead with it and you don't lead with something that OHKOs, they Swords Dance setup on the switch and begin to sweep.
If they lead with a good pokemon to set up for it to start Swords Dancing, you can't KO it fast enough and it begins to sweep.
If the gods look kindly upon you and they lead with MegaBlaziken and you lead with your counter, maybe you can win if they don't switch.
The problem is Ranked limits you to 3 pokemon because Nintendo. So you need to dedicate 1 out of your 3 to be a Blaziken killer every time or you're guaranteed to lose.
The only really good counter measure is like
>>14780929said and have a Talonflame with Gale Wings.
So great. A pokemon that EVERYONE GETS is so broken that the only way to properly deal with it is to have one other specific Pokemon and HOPE they don't fuck it up before it gets the chance to do its job.
If they lead with a Klefki, Talonflame isnt doing shit. Klefki is physically bulky enough to survive 1 Flare Blitz, which gives it time to Thunder Wave Talonflame, or even put up a Reflect to safeguard Blaziken.
Fuck Blaziken 
