3-2 Cofagriigus- non ability
2 Victini- V-Blast
Pokemon Total = 21
2 Rocky Helmet
2 Pokemon Catcher
2 Junk Arm
2 Rare Candy
1 Professor Elms Training Method
1 Pokemon Collector
2 Professor Oaks New Theroy
Trainer/Supporter Total = 20
4 Special Metal
Pokepower says that the goal of the deck is to stall with coballion while you get set up, then move damage counters around with reuniclus to be able to maximize cofagrigus' attack that swaps energy. The hydregion is not only a good attacker, but can take quite a bit of damage with such a high HP.
Your line of cofagriigus is strong, but for the combination of cofagriigus/reuniclus/reshiram to work, you'll need a stronger line of reuniclus (3-2-2). With pokemon catcher, it will easily be catcher'd and KO'd before it can work. Since you rely on so many trainers, trainer-lock with vileplume to prevent catcher really isnt an option. I would drop the v blast victini because with the coin flip risk, it will likely fail and would be a waste of a prize loss and energy. I'd drop the tyrogue as well. If you need something to sit there and take damage while you set up, I'd just use the druddigon since it can at least do damage to your opponent if they attack you.
With only one coballion in the deck that needs 3 energy for its good attack, I dont think this is an effective staller. It would be better to drop it and focus more on the hydregion line. It's a great attacker as well as having a massive HP. A line of 4-2-3 would be much stronger. I considered dropping the reshiram line as well, but figured it was a good back up attacker.
19 energy is way too much for a deck like this. Since hydregion can make any energy dark that's attached to it, maxing out your DCE is best. Adding special dark so that hydregion can hit for more is ideal with 3-4 in the deck. Since I'm suggesting you take out the coballion, you can drop all the metal energy. Since your only other attacker is cofagrigus, you should be safe with about 5 psychic energy. That should bring your energy line down to the low teens. If you really want more, I'd go with a couple of rescue energy or basic dark.
To get a fast set up, you'll need to increase your line of collector to 4 and rare candy to 3. Adding in some sage will help you get the cards you need as fast as possible. Maxing out your junk arms at 4 is essential to being able to reuse something. You might want one more twins since this deck could be behind quite often with the heavy stage 2. I'd drop the pokeball since it relies on a coin flip and we want cards that can consistently work. 1 super rod will help you recover your energy and pokemon.
You have some hand refreshers like PONT and N, but it would be best if both of those were maxed out at 4 each. If you don't have room, possibly drop some of the N. While N can be a great hand refresher and disrupter, if you don't have many prizes left, it could hurt you. If you need the extra room, it should be safe to drop the elm since the only time you'll really need it would be under trainer lock (usually communicating a pokemon in is much more effective since it doesnt waste your supporter for the turn).
By reducing your list to focus on a few less pokemon and make those lines stronger, your deck should be much faster and more consistent. I hope my suggestions are helpful!