Only cards from Ex Ruby & Sapphire, Ex Sandstorm, Ex Dragon, and Ex Team Magma vs Team Aqua allowed. However, energy from previous sets are also allowed.
x2 Horsea (Retaliate) (Dragon)-Smokescreen is always a good attack but the highlight is Retaliate. Needed for evolution.
x1 Seadra (Waterfall) (Dragon)-Needed for evolution.
x1 Kingdra ex (Dragon)-Hydro Cannon is decent but mainly Kingdra is a one energy attacker. For one energy it can do 40 damage from Seadra's Waterfall, then up to 140 damage with Horsea's Retaliate. Simply amazing.
x3 Mudkip (Bubble) (R&S)-A one for 10 with a chance to paralyze isn't bad. Needed for evolution.
x1 Swampert (Natural Remedy) (R&S)-Natural Remedy keeps it going for a while. Water Arrow is a solid one for 20 to any Pokemon. Waterfall is a decent three for 50. A solid Stage 2.
x1 Swampert ex (MvA)-The Fighting type lets me get through Water resistance and gets me a Fighting weakness bonus. Hydro Pump is a decent one for 20 that does 20 more damage for each additional energy. Crushing Wave is a solid three for 40 to any Pokemon with a chance at Energy Removal. 150 HP makes this a good Pokemon.
x3 Wingull (R&S)-Fighting resistance and a chance at 20 damage for one energy. Needed for evolution.
x2 Pelipper (R&S)-A really solid Pokemon. With Stockpile, Spit Up becomes a great two for 70 and Spit up becomes an incredible three for 60 that fully heals Pelipper. Add on Fighting resistance and no retreat cost with High Pressure System and I have a great card.
x2 Marill (Sandstorm)-A good chance to paralyze the foe. Needed for evolution.
x1 Azumarill (Sandstorm)-Drizzle combined with Max Bubbles can end up doing a lot of damage really quickly. No retreat cost with High Pressure System.
x3 Team Aqua's Spheal (Powder Snow) (MvA)-A one for 10 that puts the foe to sleep on a Pokemon with essentially no weakness and no retreat cost with High Pressure System. A great card for the start of the game.
x4 Energy Search (R&S)-Gets me Energy, mainly for use with Azumarill.
x3 Rare Candy (Sandstorm)-Gets me my Swamperts and Kingdra faster.
x3 Wally's Training (Sandstorm)-Faster evolution is needed, considering the only basic without an evolution in this deck is Spheal.
x3 PokeNav (R&S)-Gets me a card and lets me control my drawing.
x2 TV Reporter (Dragon)-Drawing.
x2 Warp Point (MvA)-A Switch and a Gust of Wind rolled into one.
x1 Professor Birch (R&S)-Drawing.
x1 High Pressure System (Dragon)-To lower my retreat cost and also get rid of any Stadiums my opponent might have in play.
x21 Water Energy-Needed.
This deck has incredible power with very strong evolutions. And it doesn't sacrifice the start of the game either, as Horsea, Mudkip, Marill, and Spheal have solid stalling capabilities.