>>25276335Is there any reason why you want to play this in Expanded? The deck would perform a lot better in Standard.
Either way, a 2-2-2-1 line of Greninja is nothing. Put it to 3-4-4-2. You don't need 4 Froakie because of Water Duplication on Frogadier. Also, run the BP Greninja alongside it, since it has better attacks and you won't be able to fuel 4 XY Greninja and the Break anyways. Or promo Greninja if you want to meme even harder.
Blastoise EX is bad and makes no sense here. Instead, run Miltank, Find Ice Articuno, Manaphy EX (better than Keldeo), 2-2 Octillery, or Shaymin. You can try a secondary attacker like Regice or Suicune, but you really don't have the energy or deck space for that.
For Expanded, your Supporter lineup should be 3 Juniper, 3 N, 1 Colress, 1 or 2 Lysandre, 4 VS Seeker, 4 Dive Ball (mix with Ultra if you have Shaymin), an Ace Spec, then a mix of Superior Energy Retrieval, Battle Compressor, or Fisherman. Evosoda and Cheren are bad here, and Rough Seas isn't that optimal in this deck. For a stadium, you can either run Virbank for those Lasers (add in two more if you do), or something like Silent Lab or Faded Town.
For energies, I have no clue why you've included DCE or Rainbow Energy here. 2 Splash and 10 Water is fine.
Here's a sample I threw together quick for you.
