So, we have pokemon that have 300 HP right? Wait, we don't? Why do we have an attack that does 300 damage again? What's that? No reason? Right!
So let's look at realistic deck options and sorry for the book in advance:
Charizard GX - Requires a whopping 5 energy attachments, discards 3 *FIRE* energy, requires bare minimum a 3-2-3 line + 4 Rare Candies OR Ho-Oh GX's GX attack to get it onto your bench along with 2 buddies which would require two attachments (DCE + Fire) on Ho-Oh GX to pull off T1. The attachments are doable on Ho-Oh for set up. Getting fire energy onto Charizard GX this way after set up is not. You can get some burning energy onto this beast, but realistically, you are looking at getting two on it maximum by the time you would use it's primary beat stick attack. Long story short, that's bare minimum 12 cards and a slew of combinations to get a powered up Charizard up and running. If you choose to go the Ho-Oh route, you have to wait until T2 to use Kiawe which is very risky. If you choose to go the Rare Candy route and use Kiawe T1, you just attached 4 energy to what is likely to be a 60-70 HP Charmander...call me crazy, but that is crazy. Thanks but no thanks.
M Charizard Flashfire/Evolutions style - Still requires a whopping 5 energy attachments, but damages itself for 50 with its attack instead. Requires at least a 3-3 line + 3-4 spirit links to work effectively. Can take advantage of Mega Turbo to hit the energy requirements along with Kiawe so you could potentially get it up and running as early as T2 without having to resort to something like Charizard's Stoke attack to make it work. You could also use a Ho-Oh GX engine to get this set up, but honestly I think it would be very clunky. Overall, I think this would be a good option, but 50 damage to itself puts it at 170 damage needed to OHKO it. That's a TON of effort to put in just to get return 1 shotted the very next turn. Pass.
M Charizard Generations style - The less discussed Charizard. Has Heat Typhoon which does 100+ damage + flip a coin for each fire energy attached and do an additional 50 for each heads. Still requires the same 3-3 line + 3-4 spirit links to get set up. Realistically, you need at least 6 fire energy attachments on it to consistently OHKO everything in the game, but it also benefits from Victini and can get charged up T1 with Kiawe and be ready to go T2 for all 6 energy required. That's a massive energy investment, but it also gives you a realistic shot at ending games before your opponent has a chance to do anything AND doesn't require a lot of items to set up. I happen to really like this one, but the flippy nature gives me pause.
M Salamence - You know, that Mega that has potential but doesn't actually work. Kiawe might actually change the dynamic for this card. It is bulky at 230 HP, is Fairy weak which is far better than being Water weak right now, and the attack gives you a base 100 damage with the option of doing more for the cost of discarding a fire energy for each additional 40 damage you want to inflict. Great idea...but I have to discard 3 energy to hit 220 and a whopping 4 energy to hit 250. M Salamence does benefit from DDE and you *can* discard 1 DDE to hit 2 of those energy discards, but ultimately you are still likely discarding at least 3 energy every single turn in an effort to KO most of the S1 GX meta and even several of the Basic GX meta. I don't think this works.
M Rayquaza Dragon Ascent style - I think this is our clear winner for the likely 1 month it will be a legal combination in standard. It requires a 3-3 line + 3-4 Spirit links to use. It has a fat 5 energy attachment requirement including one that has to be lightning. It's attack does 300 damage and you discard *TWO* energy as the cost of doing business. Now, call me crazy, but if I have a choice between running something that is Water weak vs Fairy weak and requires one fewer energy discard of ANY type (not limited to fire), still does the 300 damage I want AND can benefit from both DDE and Mega Turbo where Charizard GX cannot while still benefiting from Kiawe by slapping that energy on a much safer 170 HP Rayquaza EX, why wouldn't this be the way I would go? Beyond the desire to run a Charizard, I don't think there is any question that this is the most viable deck.
To be clear, I am not advocating any of these decks. I am not sure that any of them are viable. That said, the goal is to give a realistic comparison between Charizard GX and contemporaries that could take advantage of a similar engine with a similar beat stick. I think Charizard GX is probably my 4th choice on this list (I would take it over the M Charizard Furious Fists / Evolutions list). The other decks are going to be as (or more) consistent while not leaving the energy exposed on a tiny Basic T1. The only reason I think it is better than the Evolutions style list is because it doesn't damage itself putting into fairly easy OHKO range for a return shot leaving you scrambling to replace it. Overall, I think this is going to be a lot like Incineroar was. Fun card. Completely unplayable in any kind of competitive setting.
So let's look at realistic deck options and sorry for the book in advance:
Charizard GX - Requires a whopping 5 energy attachments, discards 3 *FIRE* energy, requires bare minimum a 3-2-3 line + 4 Rare Candies OR Ho-Oh GX's GX attack to get it onto your bench along with 2 buddies which would require two attachments (DCE + Fire) on Ho-Oh GX to pull off T1. The attachments are doable on Ho-Oh for set up. Getting fire energy onto Charizard GX this way after set up is not. You can get some burning energy onto this beast, but realistically, you are looking at getting two on it maximum by the time you would use it's primary beat stick attack. Long story short, that's bare minimum 12 cards and a slew of combinations to get a powered up Charizard up and running. If you choose to go the Ho-Oh route, you have to wait until T2 to use Kiawe which is very risky. If you choose to go the Rare Candy route and use Kiawe T1, you just attached 4 energy to what is likely to be a 60-70 HP Charmander...call me crazy, but that is crazy. Thanks but no thanks.
M Charizard Flashfire/Evolutions style - Still requires a whopping 5 energy attachments, but damages itself for 50 with its attack instead. Requires at least a 3-3 line + 3-4 spirit links to work effectively. Can take advantage of Mega Turbo to hit the energy requirements along with Kiawe so you could potentially get it up and running as early as T2 without having to resort to something like Charizard's Stoke attack to make it work. You could also use a Ho-Oh GX engine to get this set up, but honestly I think it would be very clunky. Overall, I think this would be a good option, but 50 damage to itself puts it at 170 damage needed to OHKO it. That's a TON of effort to put in just to get return 1 shotted the very next turn. Pass.
M Charizard Generations style - The less discussed Charizard. Has Heat Typhoon which does 100+ damage + flip a coin for each fire energy attached and do an additional 50 for each heads. Still requires the same 3-3 line + 3-4 spirit links to get set up. Realistically, you need at least 6 fire energy attachments on it to consistently OHKO everything in the game, but it also benefits from Victini and can get charged up T1 with Kiawe and be ready to go T2 for all 6 energy required. That's a massive energy investment, but it also gives you a realistic shot at ending games before your opponent has a chance to do anything AND doesn't require a lot of items to set up. I happen to really like this one, but the flippy nature gives me pause.
M Salamence - You know, that Mega that has potential but doesn't actually work. Kiawe might actually change the dynamic for this card. It is bulky at 230 HP, is Fairy weak which is far better than being Water weak right now, and the attack gives you a base 100 damage with the option of doing more for the cost of discarding a fire energy for each additional 40 damage you want to inflict. Great idea...but I have to discard 3 energy to hit 220 and a whopping 4 energy to hit 250. M Salamence does benefit from DDE and you *can* discard 1 DDE to hit 2 of those energy discards, but ultimately you are still likely discarding at least 3 energy every single turn in an effort to KO most of the S1 GX meta and even several of the Basic GX meta. I don't think this works.
M Rayquaza Dragon Ascent style - I think this is our clear winner for the likely 1 month it will be a legal combination in standard. It requires a 3-3 line + 3-4 Spirit links to use. It has a fat 5 energy attachment requirement including one that has to be lightning. It's attack does 300 damage and you discard *TWO* energy as the cost of doing business. Now, call me crazy, but if I have a choice between running something that is Water weak vs Fairy weak and requires one fewer energy discard of ANY type (not limited to fire), still does the 300 damage I want AND can benefit from both DDE and Mega Turbo where Charizard GX cannot while still benefiting from Kiawe by slapping that energy on a much safer 170 HP Rayquaza EX, why wouldn't this be the way I would go? Beyond the desire to run a Charizard, I don't think there is any question that this is the most viable deck.
To be clear, I am not advocating any of these decks. I am not sure that any of them are viable. That said, the goal is to give a realistic comparison between Charizard GX and contemporaries that could take advantage of a similar engine with a similar beat stick. I think Charizard GX is probably my 4th choice on this list (I would take it over the M Charizard Furious Fists / Evolutions list). The other decks are going to be as (or more) consistent while not leaving the energy exposed on a tiny Basic T1. The only reason I think it is better than the Evolutions style list is because it doesn't damage itself putting into fairly easy OHKO range for a return shot leaving you scrambling to replace it. Overall, I think this is going to be a lot like Incineroar was. Fun card. Completely unplayable in any kind of competitive setting.