User blog comment:Kogath/Monster Hunter 4 Ultimate for the Nintendo 3DS/@comment-28303251-20150919053632/@comment-5569775-20150919065332

Use a poison weapon with Grand Cham set. Try to keep it poison as much as possible. If at any point it forms the black wind barrier and you can't get close enough to hit/poison it, wait till it's flying then Flashbomb it out of the air, to try and get some hits in. Successful mounts will knock it out of the black wind barrier.

Personally, I've gotten in the habit of using a SA to fight it. Even when the black wind barrier is up, as long as I'm attacking and don't bounce the wind has no effect.