Mr Mime doesn't prevent Greninja damage from abilities, it only protects from bench damage from attacks
If you just want to counter Greninja go with this
That Sylveon just doesn't do enough and doesn't help your strategy of accelerating energy.
That Giratina card is actually pretty cool but still not a good counter measure for reasons below.
I was just wondering cause Sylveon has an attack that can remove an energy from the opponents active, and it can do 150 damage in 2 turns. I was thinking mr mime because my friend uses a break greninja deck and he always wrecks my bench with the abilities.
Anyway i went with 2 gardevoir ex and 2 megas. 3 xerneas and 2 breaks. spirtzee and a aromatisse.
That's a nice card, think i'll use it in my mega mewtwo deck haha
I've been running Greninja Break for a good 6 months now. I've been adapting it to constantly fit the new format and new Pokemon. I also have a Mega Mewtwo Y deck and gone against plenty. The Giratina card just isn't worth the space. Garbodor has a been a huge pain in my arse for months now. I've found a counter tactic which is to Lysandre Garbodor into the active, play XY Evolutions Rattata and then start Giant Water Shurikening everything again. If the opponent also plays a Garbodor or Hez Maniac your Giratina will be useless. There isn't any point in a Mega Mewtwo deck to play an ability card when your going for raw damage or using damage change if Shrine of Memories is in play.
There also aren't any Break Pokemon used outside of Greninja Break and that card has heavily dropped due to Decidueye-GX just being a better overall set. You might find someone using Talonflame Break, Delphox Break and Yanmega Break after Greninja and the only Breaks with decent abilities is Starmie, Delphic and Greninja. If you're going to shut off a a Breaks ability, you may as well shut off all Pokemon abilities with Garbodor. It is a much better setup and gives you the same effects.
What's more frustrating as a Greninja Break player, is that Garbodor can use any tool. If you do end up losing float stone via Rattata, you can attach any tool you want. My friend a few months back bad a dick move by putting a Mewtwo Spirit Link on it. On turn 2. You can play your entire hand, put Trubbish out and if you do play a Wally, you can evolve into Garbodor, put on a random tool including spirit link, and on turn one, no abilities can be played. The normal route would be to just play Ultra Ball on turn 2 to find Garbodor since you would be running Wally but it is a potential route, just not the best for Mega Mewtwo.
From personal experience I hate Garbodor. It shuts down Greninja Break and is the ultimate counter to it.