Kingdra isn't that great...you know? For those that don't know what it does, here is the spoiler:
[.] Aqua Stream: Choose any number of Water Energy in your discard pile, show them to your opponent, and do 10 damage for each Energy card. Then, return those Energy to your deck and shuffle your deck.
[W] Dragon Pump: 40 damage. You may discard 2 cards from your hand. If you do, this attack does an additional 20 damage and does 20 damage to 1 of your opponent's Benched Pokemon.
It's first attack is very hard to pull off big damage quickly. Kingdra just does 10 damage for each energy too. If decks could discard big amounts of energy a turn, Infernape lv.X would be dominating every tournament.
It's second attack doesn't do enough damage to OHKO anything other than a basic. 40 for W is not bad, but on a stage 2, 40 damage isn't worth building a line to. You can use the second attack to fuel the first attack, but it would take 5-6 turns of discarding 2 water energy a turn just to even pull off a decent Aqua Stream. By that time, Kingdra will be KO'd. What's even worse about Kingdra's attack is that you don't get no extra bench damage if you choose to not discard 2 cards from your hand. You either discard 2 cards (no choice of 1 or 2) and hit 1 pokemon for 20 (not worth it) or don't discard 2 cards and do a measly 40 damage.
I don't see how you can even put this card on the same level as GG where Gardevior lv.X OHKO's anything in the game with the least HP left for PP, and Gallade can OHKO most anything by flipping over all the prizes. No deck in the format can pull off the damage that this deck can for as little resources as it takes it. An early Gardevior lv.X or Gallade can win games. An early Kingdra does what?
In the last 60-card deck tournament I attended in Japan, a very good Tentacruel/Lanturn deck beat my AMU deck in the finals and won the tournament. I hadn't even read the cards properly before, and was surprised and impressed by how good the deck worked. The damage spread is so effective and scary.