So there's a Ray card. I can see a enormous potential in this card. It seems like the Pokemon Company has been preparing metagame's terrain for this debut, even changing the dual type cost for Grass type (keeping fire would make rayquaza super uber because of kiawe and volcanion). For me, better than Bulu because this one needs Vikavolt up almost every turn and energy recycler strategy is not something you want to miss
Let's see why.
First of all, lets take a glance at the ability: discard 3 to possibly attach 1 sucks, having a small chance to waste important cards early game is even worse, but if you are able to somehow manage your topdeck using things like mallow, you might be able to combine these cards with baby raikou to attach up to 3 energies in one turn (at least, and not counting elixir, letter, lady, magnezone, vikavolt...). Could be useful as energy burner for eventual Electrode GX early appearance. Situational, I would not rely on this strategy.
Attack: very good, outstanding attacking power, damage stacking potential is skyhigh, with right support it's not difficult to have up to 7 energy in play T2-T3. Darkrai EX was significantly weaker than this and still managed to reach 180 dmg midgame
GX: prevents early game bad luck / helps bench structuration / accelerates for REAL your game / assures THAT key late game draw / forces opponent to N at situations where you cannot afford to take a Guzma; if he doesnt N, you'll have a legit sycamore + Lapras collect + Turn's draw hand, which is superb.
Drampa's Big wheel is awesome too, but discarding cards instead of shuffling them back is part of this card's strategy and is arguably more helpful in certain situations. If discarding bothers you, Lele-->Cynthia.
Weakness to fairy may hurt a little, as gardy only needs 1 energy to KO, but she's nowhere these days, and if it really becomes a real threat in meta, just run 4 unity energy and throw a metal type tech (kek r u serious) or weakness policy.
Not having fight resistance is a SHAME.
Eletric, Grass and Dragon are types who have lot of support and really lack real stars (excluding vikabulu) to make their potential really shine. I've got some cards who can be options in this situation:
Max Elixir: 4 copies with lots of energies to ensure, at least, 3 attachments.
Volkner searching an energy + item is not bad at all, maybe 1 copy will help magnezone/vikavolt evolve.
Lance Prism Star: must have in all Dragon decks, can bring to early game any combination of Ray, Altaria, or even salamence GX tech (that 3 retreat cost...)
Zinnia: nice supporter, if you are not running magnezone. To play with Vikavolt. Strong, but situational. However, in this ultraoffense meta, who knows?
Sky pillar: extremely useful against buzzwole or glaceon/greninja. Stadium war is a thing nowadays, but its helpful anyway. Helps voltorbs to not easily die to jet punch/frost bullet/shurikens.
Wishful baton is arguably better than CB in order to keep those 3 energies around. CB can always help to reach key KOs faster, but any unexpected Rayquaza KO will really mess your game. Would stay with WB, as with it, any Rayquaza loss can be easily handled.
Lady + Professor letter + Magnezone: extreme aceleration. Some energy recover from discard combines perfectly, as energy burn here is HUGE.
Vikavolt line 3-1-3: much more conservative option than magnezone, limited to 2 attachments per use, but it works alone, not relying in big card combos. 2 Vikavolts up = almost instawin.
Baby raikou: somewhat interesting card with nice attack, but only useful in early game, as grass/eletric has better options for mid-late game.
Shining legends Venusaur: something to stay tunned in. If grass gets good support in upcoming sets, double grass energy might be broken, because +60 dmg for 1 basic is stupidly broken. 2 elixir + lurantis attack = 240 dmg up not counting turn's energy.
Lurantis GX: Nice energy attachment, but gives so much momentum for buzzwole/necrozma/glaceon. Combo with Venusaur probably should be avoided by now, as magnezone/electrode/lady is a literal energy rain. Use it if you feel you can't handle buzzwole's advantage against magnezone.
Electrode (evolutions)/Electrode GX: 1 prize for 60dmg or 2 prizes for 150 dmg. High risk, high reward situation, putting these energys in the right mon surely means 2 straight opposing GX KOs. Baby doesnt need to have energy in discard pile, only gives 1 prize (which is good most of time), but Hammer/guzma is a problem for baby electrode. Electrode GX, in other hand, is essencially extreme energy bombing for 2 prizes. This is not bad, as it allows player to attach 5 energy from discard in any way you want and gives you 99% chance of OHKOing opponents active mon. Some supporters with broken effects can only be used when your opponent KOed your mon in previous turn, so it can be huge in the right moment, combined with a key Guzma (presumably early-mid game), to reach that needed one shot, while keeping the second rayquaza ready in the bench for revenge killing. 1-1 or 2-1 for Elec GX, as you only want 1 electrode per game
Altaria: 20+ dmg is always welcome, but with these already nuclear damages Ray intends to reach, accurate calcs are needed in order to discover Altaria's real usefulness, as I tend to find that even CB is not that useful to Rayquaza.
Latias Prism Star: magnific and disappointing. Attaching from discard pile means she wont be useful in early game to help setting up, which is a huge flaw for a frail one-time using mon with no other attacking options. If you somehow manage to send 3 energies to discard in T1-T2 while having an energized latias in the bench, this girl will give you a hell lot of striking force. Counterproductive with Electrode GX, though.
Mew/Mew-EX: tech against buzzwole. 3 energy= 180 dmg, not counting the ones attached to your benched pokemon.
Rayquaza in Vikabulu: not that good, as rayquaza and tapu bulu are counterproductive because the energy management requirements for them are somewhat different.
Feel free to discuss, rate my thoughts, or give different ideas.