I have been playing this deck recently, and modifying it many times. I chose to take the consistency road for now, thinking it's the best for now.
I think Dragon Mega Rayquaza is great right now (almost unfair to be honest) because since we rotated into Primal Clash on, EX decks have been showing up a lot more with the likes of Mewtwo, Volcanion, Colorless Rayquaza and Mega Gardevoir. My list right now looks like as follows and has yet to be effectively tested.
Pokémon (11)
1 Hydreigon EX RSK
3 M Rayquaza EX RSK61
3 Rayquaza EX RSK60
4 Reshiram RSK
Trainer (37)
3 Scorched Earth
1 Hex Maniac
2 Lysandre
4 N
1 Pokémon Ranger
4 Professor Sycamore
3 Mega Turbo
3 Rayquaza Spirit Link
1 Special Charge
4 Switch
4 Trainer's Mail
3 Ultra Ball
4 VS Seeker
Energy (12)
Double Dragon Energy x4
Fire Energy x8
Here's why I run each card:
1 Hydreigon EX: He allows my dragons, all of my Pokémon, that all retreat for two, to retreat for free when there is a Stadium. I only run one though because I hate opening with just him and he is just a bonus on top of the status breaking switch. He can also use Shred which does 80 damage pretty much no matter what.
3 M Rayquaza EX: My main attacker. He does 300 damage which is enough to KO anything (now in the Aurorus and Floette less format anyway). He is the one I want to power up and thus I run a thick line.
3 Rayquaza EX: He evolves into Mega Rayquaza. He can also Dragon Strike for 130 damage if needed. I use the Dragon version because it beneficiates Reshiram and Hydreigon EX's abilities, has more health, more fitting attacks and can take double Dragon energy as well.
4 Reshiram: His Turboblaze ability allows me to power my Rayquaza up more efficiently by attaching an extra energy from my hand once per turn, per Reshiram. He can also attack in a pinch I guess. I play four so that I have over 50% odds of starting with him, which I want.
3 Scorched Earth: Any excedentary red energy can be transformed into two new cards and fuel up my Mega Rayquaza faster when I have Mega Turbo in my hand.
It also serves as a Stadium to use with Hydreigon EX.
1 Hex Maniac: My deck (despite Hydreigon) destests EX immunity and I have to do something about that. Also, Greninja is popular, so we need an answer to this Shuriken multi-attack cheater... I mean totally fair nice ninja deck, right?
2 Lysandre: Two is the amount. This is extremely important in that you want to choose who you kill. 300 to a one prizer won't get you far, you want the big and/or dangerous guy.
4 N: This is a Professor Oak's new Theory at the start of a game. It also helps if I am somehow losing and if I got mulligans and go first. This happens since I only run 8 basic Pokémon (it's less than 1/7 of my deck). It can also obliterate big hand decks like Metagross or Noctowl.
1 Pokémon Ranger: This is especially for Giratina EX as attaching Double Dragon Energy to my new Rayquaza is vital. It also helps against Jolteon and Glaceon EX. It can even be used in the rare case where I have to re-use Dragon Strike after I flipped tails on the previous turn.
4 Professor Sycamore: This deck often gets into a small hand and the draw from this card is just too good, even for the sometimes nasty price. It is almost always worth it. You should play four as you do in every standard and expanded deck.
3 Mega Turbo: It synergizes well with Scorched Earth and the energy discard when you attack. It really helps in getting back to five and striking once more. I play three and not four because I do not like seeing it when I start and there is another way to get energy back to be reused.
3 Rayquaza Spirit Link: Here is a thing that differenciates this mega evolution from mega Charizard: it has a Spirit Link, so you can mega evolve and then attack (after playing Mega Turbo if you wish). Let's face it: one of the greatest early game pressures you can exert is a turn two Dragon Ascent.
1 Special Charge: I kept this instead of Super Rod. Only 1% of games required that I bring back a Pokémon and this card technically gives me 4 energies back that I can use for any attack. Yeah, no dilemma there. I can also cancel losses due to hammers in some way.
4 Switch: Yes, I have Hydreigon. But the following happen: my Hydreigon is prized and/or I cannot find it or a Stadium, my Hydreigon faints, gets discarded by the opponent, I get afflicted by Paralysis or Sleep or my Hydreigon itself is sent out (its retreat cost is 3 or 1 with a Stadium). With ability locks like Garbodor getting more importance, I cam't just always opt for retrating through Hydreigon's ability. Besides, you can only retreat once per turn. Switch retreating can be done in cases like having to Turboblaze when you had a Rayquaza active, Turboblazing multiple times and then sending out Rayquaza or if the opponent afflicted your attacked with something like preventing him from attacking (or if you flip tails on Dragon Strike). I therefore think it's worth running four.
4 Trainer's Mail: This is a way to reach for something you want and/or need. You can get any Trainer (except the mail) from the top 4 cards of your deck. Chances are you will find either the Spirit Link or Mega Turbo you wanted (one of them at least) or run into the VS Seeker or draw Supporter you wanted to keep drawing or anything else you may need.
3 Ultra Ball: They are the best Poké Balls. They are great in this deck too. When you run into one, you should probably think of getting your Hydreigon out or a Mega Rayquaza. The 2 card loss is totally acceptable considering you run 4 Sycamore and it can just as well be the next card you use.
4 VS Seeker: An almost broken item in my opinion, it gets you any supporter from your discard pile (that you used or got in there in another way such as Sycamore or Ultra Ball). You can recycle Ranger and Hex Maniac but you are mostly going to use this for Lysandre, Sycamore or sometimes N (for later game disruption and conservation).
4 Double Dragon Energy: If you play this deck, you have no choice. This is two rainbow energy to a Dragon Pokémon with no negative side effects. It allows averyone in your deck to attack, but the best in that is that it allows your Mega Rayquaza to attack faster. Besides, it makes it so you are not forced to run other energy types. It is painful to lose that, it's the only downside I can see now that Aegislash is out.
8 Fire Energy: It is the main type of energy Mega Rayquaza needs to attack. It is compatble with Turboblaze and Scorched Earth. Due to Double Dragon Energy, you can run only these for you basic energy. Eight seems to be ideal here, allowing you for enough energy for the entire game without having it invade your starting hand (it almost never does and it's good this way because a good starting hand must have a bit of everything in Pokémon, energy and a draw Supporter as well as maybe an item or two you can use or lose easily now).
This is it for my list. Now, here are a few cards you may consider running in your own list of this awesome Dragon deck:
1-1 or 2-2 Clauncher and Clawitzer STS: Clawitzer's Mega Boost ability allows you to attach one special energy card from you hand to one of your mega evolution Pokémon once per turn per Clawitzer. Make sure you run float stone or lots of switching cards if you play this though, and you can include dive ball too. Raibow energy can be a thing too because it's another special energy that will help you beneficiate from this ability. I do not like it a lot though because you normally will attach about four special energies per game so it's a lot less useful that Reshiram that also fits a lot better with the deck. It is also a frail Pokémon that you never want to open with as the only one in hand. Nothing keeps you from trying it though.
1-3 Solrock PCL: Its first attack allows you to search your deck and get 2 special energy cards out for a single energy. Again, there is a reason I don't really recommend it and it is N's presence as well as the fact it forces you to play a few things just for it.
1-2 Bunnelby AncientTrait PCL: Its attacks can help at times. Rototiller shuffles a card from your discard pile into your deck, such as a Double Dragon energy or anything you may be missing right now. It can do that twice a turn thanks to its ancient trait and for a single energy of any type. It can also serve as a way to end a game when your opponent's deck is nearly gone.
2-4 Shrine of Memories: It allows Mega Rayquaza to use Dragon Strike when beneficiating from more health and an ancient trait: Delta Wild, essentially a resistance to grass, fire, water and the lightning type. This is useful when you do not yet have enough energy or are batling smaller Pokémon you do not want to have to waste two energies on.
1 Ace Trainer: Much like N, it can help you when you are losing or in that situation where your Reshiram goes down and you are one prize behind.
1 Fisherman: This allows you to grab four basic energies from your discard pile and put then directly into your hand. It 's useful with Turboblaze and when you are getting low on energies.
1-2 Fairy Drop: When your injured Pokémon has a Double Dragon energy attached to it, you may use this item to get 50 damage off of it. This is useful to make your beasts last a turn longer.
1-2 Professor's Letter: This works rather well with Turboblaze that requires fire energy cards in your hand. It can also help you draw as you can discard one with Scorched Earth to draw two cards.
3-4 Puzzle of Time: Playing one can help you top deck what you wish to top deck but the true power comes when you play two at once. When you do so, you take any two cards from your discard pile and get them into your hand. A great play in the late game.
1 Super Rod: You may want to get your fire energy back in a certain way beyond Mega Turbo and this works too. You should consider this over Energy Recycler, I think, because it also allows you to recycle Pokémon like that Mega Rayquaza you may have discarded at the beginning of the game.
1-2 Lightning Energy: You can play these to deal with the likes of Giratina EX and any deck against which you have trouble due to hammers or such. They can also be recycled with Mega Turbo. Note that these lightning energies are far from mandatory because you can, in these situations, attach double dragon energy only to attack and then discard it yourself to pay the price of instant doom.
This is all I have to say for now about my favourite deck of the format at the moment. It is a deck that does well against three of the four benchmarks right now and I hope you can give it a try.
I hope this helped you. I will make more posts eventually. Thanks to you if you took the time to read.
