Only card from Expedition, Aquapolis, and Skyridge are allowed. However, Energy cards from previous sets are allowed.
x4 Poliwag (Skyridge)-Sleep Bubble is decent, a one for 10 that puts the foe to sleep. Doubleslap can do 40 damage for two energy. Needed for evolution.
x3 Poliwhirl (Skyridge)-Twiddle is a decent stall tactic. Double Kick can do 60 damage for three energy. Needed for evolution.
x1 Poliwrath (Expedition)-Can do a lot of damage very quickly. If my Active Pokemon is about to go down, I just use Plunge. Then I hit hard with Water Punch.
x1 Politoed (Skyridge)-110 HP is nice. Sudden Growth helps a lot. I can use it to get Energy Splash set up and then use that to give Energy to my Pokemon or I use Sudden Growth and then next turn have Poliwrath use Plunge and quickly do a lot of damage. Frog Hop is a decent three for a chance at 50 attack. Energy Spalsh does 70 damage and also helps my bench out. The five energy is not so much when Sudden Growth is considered.
x4 Eevee (Aquapolis)-Can do 20 damage for one energy. Needed for evolution.
x3 Vaporeon (Skyridge)-Self-healing protects it from Special Conditions. Aqua Trick does 40 damage for three energy and can also disrupt my foe by moving their energy to a Pokemon that doesn't need it.
x4 Lapras (Skyridge)-A 60 HP basic with a weakness to an uncommon type. Assist gets me Supporters, so that is nice. Hypnoblast is decent, doing 30 damage for three energy and having a chance to put the foe to sleep. Lapras can help me gain control of the game at the start.
x4 Oracle (Skyridge)-To control my card drawing, getting me needed cards.
x3 Bill’s Maintenance (Expedition)-Card drawing.
x3 Pokemon Nurse (Expedition)-Healing. I can use it with the Pokemon Poliwrath just used Plunge on, seeing as that Pokemon is going to likely be damaged a lot. I get a free heal for that guy from this.
x2 Warp Point (Expedition)-A Switch and a Gust of Wind rolled into one when played right (always).
x2 Seer (Aquapolis)-Gets me Energy to use with Politoed.
x1 Mary’s Impulse (Expedition)-Card drawing.
x1 Fisherman (Skyridge)-To get back Energy I lost back into my hand to be brought back onto my Pokemon with Politoed.
x24 Water Energy-Needed.
This deck is centered around Poliwrath. I take control of the game early on with Lapras and Vaporeon, then get Politoed and Poliwrath out through my card drawing. Politoed gets Energy on it fast, then Poliwrath uses Plunge to get those Energy and do a lot of damage. So yeah, it's a Rain Dance deck.