Silvally-GX is a fun card to play around. Post-rotation opens up a bit of grounds for it on viability but I personally tend to still see it as gimmicky and more of a card to counter the meta rather than a drive for a deck. Ho-Oh-GX also seems like it's an in interesting spot after the rotation due to losing its obvious partners we had in sets like Steam Siege.
Let's see what we've got here, allow me a few moments for my thoughts.
Pokémon:
➤ The only positive implication I see by using Entei-GX, and the one which you have stated, is the ability to drop Brave Burn GX to take a knockout on a benched GX to take a knock out
(Burning your GX attack to take one prize in a situation like that is hardly something I see as being worth the play.) and in a situation like this, the straight 150 from Brave Burn GX won't be enough. The only Pokémon-GX that's prominent in the meta that can be knocked out by it
clean is Marshadow-GX, and jury's out on if it's even prominent. Really, it's a lot better of an idea to play a Guzma to bring up said GX and drop Phoenix Burn on it using Ho-Oh-GX, and saving your GX attack for a much needed Nitro Tank to close the mid- or late-game.
➤ With that being said, raise your count of Turtonator-GX, 2 is the lowest I'd play, 3 the most. 1 is hardly enough as it can be quite a strong secondary attacker. Shell Trap can apply some much needed pressure on harder hitting threats with higher HP counts
(As a Gardevoir-GX player, I can admit Shell Trap can put a Gardevoir-GX in an interesting spot.) as well as Bright Flame hitting for a solid 190 with a Choice Band, and of course, a more reliable count to set off your Nitro Tank GX when needed.
➤ I'm not entirely confident on this, though raising Dawn Wings Necrozma-GX to 2 can be considered in case the first is prized or just being in a hard spot. It's more a safety slot than needed, so it should be tested before making your decision.
➤ I really don't like the count of 2 Tapu Lele-GX after the rotation, as you have a lot less to work with in terms of drawing cards, I believe a third should now be heavily considered in almost every deck as you have less resources in your deck devoted to being able to draw into your needed supporter. Wonder Tag wins games.
Trainers
(Thank you for formatting them as Supporters/Trainers/Tools):
➤ I'm not fond of only playing 1 count of Lillie. Before the rotation, a deck like Volcanion-EX was one of the only ones you would ever see Lillie ran in as it was one of the best engine to fit the card in. Nest Ball/Lillie is a wonderful first-turn engine that I'm personally incredibly fond of that can work as a wonderful back-up engine if you're unable to hit the optimal turn 1 Kiawe.
➤ With that considered, I'd also raise your Kiawe count by 1, just to be able to more reliably set it up on Turn 1. Jury's out on that one, though, if you only need 2, play that.
➤ 2 Copycat is too heavy. Unfortunately in almost every situation you'll be copying 6 at most, meaning you're just playing a less reliable Cynthia. I'd advise dropping to 1 and just playing a higher Cynthia count.
➤ I'm not convinced on Tate and Liza, especially when your deck revolves around giving your Basic Pokémon free retreat. You don't need the switch effect in an optimal situation, and why use Shuffle-draw 5 when you can Shuffle-draw 6? However, I say "an optimal situation" because playing Silvally you'll always find it being locked active. This is why I don't suggest dropping the card. Play with 2 and consider dropping to 1. Let me know how that works for you, I'm curious.
➤ Counter Catcher seems like it's really not fit for the deck. Playing a big basic deck like this, you're most likely going to want to keep the lead during the game and don't have the highest comeback potential, with the possibility of the card being useless. Consider playing a fourth Guzma instead.
➤ Psychic Memory is a card I don't really ever see you needing. With the two main counters for it either being removed from the format
(Gallade BKT) or seemingly having a positive match-up
(oneshot potential with Turtonator-GX and Ho-Oh-GX as well as resistance with Ho-Oh-GX) against it
(Buzzwole-GX) I don't really think it's necessary.
Your Energy seems fine. Play around with it a bit, but I think 13 is a solid count.
If there's anything I can see just from quickly looking over the concept, you're going to need more consistent ways to discard Energy. You don't have Steam Up anymore.
I'm not the most confident in some of these calls due to not having played Silvally-GX since its release in Crimson Invasion with Volcanion-EX, and not being sure of how the rotation looks for either Silvally-GX, or Ho-Oh-GX. With that being said, however, I hope my thoughts can lead you somewhere.
Hope this helps!
@Xezool
