balanced

The best thing you can do with this deck is that you can equip Weezing with a helmet in an active position and have Muk charging energy on the bench, with Weezing you poison and change to Muk to take advantage of its damage bonus for poisoned pokemon.

The support cards are Koga, Leaf, which will allow you to change position Pokémon, the best is Koga, since it returns it to your hand and allows you to summon it full life again.

¡Only Dark Energy!

The strat is simple: 

1. Get Hypno on the Bench and Weezing (with 1 dark energy) on the Active Spot.
2. Use Hypno's ability and attack with Weezing.
3. Let Darkrai EX accumulate energies on the Bench and/or give Weezing a Rocky Helmet for extra chip damage.
4. Enjoy dealing 50-90 damage per turn plus having a 62.5%-75% chance to avoid damage on your turn, every turn (once set up).

Extra tips:

Replacement deck for the Darkrai EX meta with Magnezone until you have all the cards.

Toxicroak is more luck-focused unfortunately but with a well put coin toss it can knock down anything in a couple of turns.

Deck with only dark energies.

Send Druddigon ahead to die with RockyHelmet and run GiantCape on Darkrai or Toxicroak as needed.

Toxicroak should be used as a finisher, prioritize loading Darkrai if possible.

Deck more reliable and less tied to counterpart luck with LickilickyEX. More defensive.

Dialga in front, 2 energy as soon as possible, Giant Cape to help tank the first 3/4 turns.
Give the energies to whoever is on the bench, possibly Meltan -> Melmetal.
Melmetal should be managed with RockyHelmet and keeping potions for him.
Blows of 120+RockyHelmet are enough to knock down just about anything.

Very simple and fast deck. 
If you can get Manaphy and Vaporeon turn 2 you can already attack with Palkia for 150 damage.
You tend to turn 3 almost always attack with Palkia.

Plain and simple.
Druddigon in front with helmet to stall. 
Only water and lightning energies. 
A Dawn to make unexpected comebacks.
A Pokemon Communication to help that once in a while.

Very balanced deck that requires you to always believe in it. With Dragonite you could be down 0-2 and come back to 3-2 in 1 turn. It is much quicker to build up than it looks.