2-2 line of mandibuzz [blindside]
2-1-1 line of kingdra [snipe for 30]
2-2 line of vaporeon [dual splash]
Pokemon Total = 22
2 rocky helm
2 junk arm
1 max potion
2 rare candy
1 flower shop
1 sage's training
1 elm's training method
1 team rocket's trickery
Trainer/Supporter Total = 20
4 double colourless
4 special dark
9 water energy
1 dark energy
This deck is all about spreading damage and snipping. Each pokemon has an attack that instead of doing damage to the active, does damage to the bench. While this is great in the late game (you typically end up taking a lot of prizes at one), it's horrible in the early game since it will often let your opponent set up before you start doing real damage. To make this deck stronger, I'd focus on only the hydregion and the mandibuzz. You don't have any way of accelerating energy onto the field (emboar, feraligatr, ampharos, pachirisu/shaymin, etc....) so you'll need to make your attachments worth it. I would increase your hydregion to a 4-2-3 and your mandibuzz to a 3-3. Add in a cleffa for a fresh hand (and as a possible staller) and a couple of shaymin to move energy around (once one hydregion is about to be KO'd you just shaymin it onto a different one and switch out).
Without the water pokemon, you can drop the water energy and rainbow energy leaving only the DCE and special dark. I'd also include basic dark to bring the count up to 12. That should be more than enough energy. The extra space in your deck will allow for trainers and supporters that will get this deck set up faster.
You''ll need 4 collectors to get those basic pokemon on the bench as fast as possible. 4 rare candy and 3-4 communication will ensure that you can get hydregion up fast as well. 3 catcher will let you drag up big retreaters to attack while you also are able to do damage around them. For recovery, I prefer super rod since you can reuse it with junk arm (which I'd max out at 4) and doesnt use your supporter for the turn. You have a heavy retreater at your main attacker so I'd include 2 switch in the deck (especially for switching out your hydregion after you used shaymin).
The rest of the deck should go to hand refreshers/draw support - 4 PONT, 4 cheren and possibly 2-3 twins since you might lose a prize or two while getting hydregino set up. I'm on the fence with the rocky helmet. I think it could be useful in a deck like this, but if you need room for some of the other suggestions I made, I think putting those in would be more beneficial. Cards that I think are safe to drop are max potion (you don't want to discard special energy since you cant get them back from the discard pile), elm, team rockets trickery and bianca. I'm thinking that you don't need the sage either, but it could come in handy early in the game. I would just hate for you to discard special energy with it.
I think hydregion is one of the best noble victories cards, but sadly I haven't seen it working very well in tournament decks. Perhaps with the suggestions I made to your deck, you can change that!