There are 2 ways to prevent this move, and I think you should use It to save your rankings.And for some help before Regionals, There Is 2 Ways to stop Gardevoir Lv.X's Bring Down. Holon Energy WP, because If The Pokemon Has a basic Water Energy that Holon Energy Is attached to, Prevent All Effects of an attack,Excluding damage done to your pokemon that Holon Energy Is attached to. And another way Is If you have a very low pokemon out In play and another pokemon with the same HP, As long as those 2 pokemon have the lowest HP as your Pokemon In play, You will be safe. There are many ways to stop Gallade,Quick knockouts Like 80 damage on the 2nd turn and 20 to the bench of course. Or maybe Darkrai/Lucario will be a good combination. A Flygon EX Is Gallade's Nightmare, Because Of Fighting Resistance -30 and Psychic protector which may reduce any damage by 40. And 150 Hp, 3 COLORLESS energy for 70 damage. You can just do BOOST ENERGY, Then Lucario LvX will use stance then Close Combat then Aura Sphere with maybe Plus Power then Wow, Your Nightmares are over. But If You want to use that combination, Run 3 Premier Ball or 4 because Lucario LvX can keep coming back from the discard pile and giving your opponent trouble.