To accompany the suggestion I made about a TCG league, I've decided that I've post a Water themed deck I put together soon after the release of the Boundaries Crossed set. Feel free to play/mod it as you choose, as this deck is already proving to be an enormous threat in the current TCG metagame.
The Emperor's New TurtlePokemon
Squirtle (BC-29) x3
Wartortle (BC-30) x2
Blastoise (BC-31) x3
Piplup (DE-27) x3
Prinplup (DE-28) x2
Empoleon (DE-29) x3
Keldeo EX (BC-49)(BC-142) x4Items
Super Rod (NV-95)(DRV-20) x3
Cilan (ND-86) x2
Skyla (BC-134)(BC-149) x3
Cheren (EP-91)(DE-91)(BC-148) x4
Rare Candy (DE-100) x3
Potion (BW-100)(BC-132) x2
Computer Search (BC-137) x1Energy
Water Energy (BW-107) x22
The main focus of this deck is to quickly get Blastoise and Keldeo in play. Blastoise's ability Deluge allows you to play as many water energy as you have in your hand every turn. Keldeo's Secret Sword attack does a base 50 damage but gets a 20 damage boost for every Water energy attached to it. Keldeo's Rush In ability allows it to force it's way to the active pokemon spot which can be used offensively to come in and sweep, or defensively since a pokemon the leaves the active spot is cured of all status. Even if they can stop Keldeo, Blastoise's Hydro Pump is similar to Secret Sword however the base damage is 60 and it gets +10 for each water energy attached. If your opponent plays Grass types to counter your Keldeo, Empoleon's weakness is Electric and it's attack takes 1 Water energy and does 10 damage for every pokemon in play(including your opponent's). Empoleon's Diving Draw ability is excellent tech for this deck as it lets you discard 1 card to draw 2. Super Rod allows you to take a combination of 3 cards (Pokemon and Basic Energy) from your discard pile and shuffle them back into your deck. Cilan lets you search out 3 basic energies in your deck and adds them to your hand. Skyla lets you take any 1 item card from your deck and add it to your hand. Cheren lets you draw 3 cards. Rare Candy lets you go straight from Squirtle to Blastoise or from Piplup to Empoleon allowing you to set up everything you need to sweep by your second turn if you're lucky enough. The Potions are in here to increase the survivability of Keldeo and Blastoise. 22 energies is a lot to run in a deck, I know, but this allows them to be discard fodder and still maintain the ability to flood the field(no pun intended).
Eviolite (NV-91) Eviolite is a tool you can equip to any basic pokemon ( Keldeo
) and it reduces the damage taken from attacks by 20.
Ultra Ball (DE-102) Ultra Ball allows you to Discard 2 cards to search out any pokemon from your deck.
Pokemon Catcher (EP-95)(DE-111) Pokemon Catcher allows you to force your opponent's active pokemon to their bench and bring out whichever one you'd like to stare down.
Energy Retrieval (BW-92) This card allows you to take 2 basic energies from your discard pile and add them to your hand.
Energy Search (BW-93)(BC-128) This one allows you to take 1 basic energy from your deck and add it to your hand. Cilan is a lot better at this, but with only being able to play 1 supporter per turn, this allows some extra wiggle room.
N (NV-92)(NV-101)(DE-96) If you have a tendency to draw bad hands, try running N. N shuffles your and your opponent's hands into your deck then lets you draw cards equal to your remaining prizes.
Bianca (EP-90)(BC-147) If you run through your hand too quickly, Bianca lets you draw until you have 6 cards in your hand.
Hugh (BC-130) Hugh makes you and you opponent draw or discard until both players have exactly 5 cards in hand.
Sorry if this was a little long-winded, but since most members don't know anything about the TCG, I tried to be as thorough as I could but I can always clarify more if needed.