Hi, it's nice to see other people enjoying the Alolan Ninetales GX card! I personally think it is a great card. In my opinion, you don't really need some of the cards in the list. You could take out the two Rayquaza, since you already have a way to accelerate Water Energy in your deck (Aqua Patch). Sure, Rayquaza could be great to start with, but I think Alolan Vulpix is a good option too (because of its first attack); I know starting with Alolan Vulpix is risky, because it can be easily ko'ed, but two Tapu Lele GX (or one Tapu Lele GX and one Shaymin EX - or maybe an Oranguru) could take the two Rayquaza's spots. Tapu Lele GX not only has a great ability, it is a good secondary attacker too that can easily fit your deck, since you are running 3 Double Colourless Energy (I'd recommend adding one more copy of DCE). I'd take out the Float Stone too, since you are running two Manaphy EX that grant you free retreat. You could play an Escape Rope and a single Wishiwashi (the one with the Cowardice Ability) instead, since Wishiwashi lets you bypass the once-per-turn retreat rule: after attacking using Blizzard Edge, you could retreat your active Alolan Ninetales and send Wishiwashi to the active to charge up your Ninetales again using Aqua Patch; then you could use Wishiwashi's Ability to take it back to your hand and send the fully charged up Ninetales back to the active spot, attach the one-per-turn energy and attack again with Blizzard Edge.
You could try adding some more Ultra Ball or Dive Ball by tweaking the deck here and there.
Other possible tech Pokémon for this deck are Palkia EX, Glaceon EX, Sudowoodo (the one with the Roadblock Ability), although I'd recommend to keep the deck list as simple as possible. You could even try adding one Espeon EX as a tech attacker to devolve damaged Pokémon you sniped before with Ninetales' Ice Blade attack. Also, you could play a Remoraid-Octillery line (2-2, 2-1 or 1-1) as draw support instead of Tapu Lele GX and/or Shaymin EX for a more budget-friendly version of the deck.
4 copies of Puzzle of Time would be a nice addition too, because they can let you take your Aqua Patch cards back from the discard pile when you play two of them together.
I'm definetely going to try different builds of the deck, just to see which one works better/fits my playstyle. I hope you'll find this helpful! Let me know if you have anymore different ideas, I love the Alolan Ninetales GX deck and I'd like to improve it as much as possible.