Path to Perfection — Mewtwo & Mew-GX / Welder’s Unexpected Return

Mewtwo and Mew-GX / Welder is a deck with a strange history. It started off in the most impressive way possible, winning Worlds on the very first weekend the deck existed. It had massive success in the Ultra Prism-Unified Minds format, winning the three biggest Regional Championships of that time period (Cologne, Atlantic City, and Knoxville). After Cosmic Eclipse came out, Mewtwo and Mew-GX suffered from the rise of Keldeo-GX, among others, but it was still one of the most successful decks around. Then, Welder stopped being so strong when Sword and Shield was released, partly due to the new first turn rule. Mewtwo and Mew-GX did win the Oceania International Championship, but beyond that, it accomplished little. Finally, Rebel Clash put a nail in the deck’s coffin, with the rise of Dragapult VMAX, a card that could easily beat Mewtwo and Mew-GX due to its Weakness. Jirachi-GX and Weakness Guard Energy were both possible answers, but they were countered, respectively, by Power Plant and Crushing Hammer, two cards that saw plenty of play in Dragapult VMAX decklists. Even without the Weakness, anyway, the matchup wasn’t great for Mewtwo and Mew-GX.

(There were other variants of Mewtwo and Mew-GX that saw play, and even success, during last season; Mewtwo and Mew-GX / Malamar and Ultimate Mewtwo and Mew-GX were both serious competitors. However, they’re not the focus of this article.)

Then, as the new season starts, Mewtwo and Mew-GX is once again at the forefront of the metagame. It was the revelation of the first week of the new format, as it won several online events. This is a surprising turn of events, especially since many players expected the deck to die out! A deck slowly losing relevance through the course of a season is nothing unusual (think of how the once mighty Gardevoir and Sylveon-GX has fallen!), but that deck then finding a new life in the next season is stranger. This is especially noteworthy in the case of Mewtwo and Mew-GX: due to the nature of the Perfection Ability, Mewtwo and Mew-GX gets better as it gains access to more GX Pokémon whose attacks it can copy. New sets in the Sword and Shield era don’t have new GX Pokémon, so Mewtwo and Mew-GX generally doesn’t gain as much from them as other decks. On the other hand, losing four sets of the GX era to rotation means that it lost plenty of usable Pokémon.

So why is Mewtwo and Mew-GX good again now? And, perhaps most importantly, how should you build and play Mewtwo and Mew-GX? I’ll try to answer both of these questions in this article. Since Mewtwo and Mew-GX is a toolbox deck, this means that I’ll also discuss the many possible options for this deck and what they can be used to tech against!

A Surprising Comeback

This is my attempt to answer the question “Why is Mewtwo and Mew-GX good again?”. If you do not care too much about theory, feel free to skip this section!

The first thing to note is that Mewtwo and Mew-GX didn’t lose that much in the rotation.

Although many Pokémon-GX rotated out of Standard, only two of them saw serious play in this archetype: Solgaleo-GX and Magcargo-GX. These are important losses, for sure: Solgaleo-GX’s Turbo Strike was generally the default attack you’d use when you couldn’t get an OHKO, and would be used to charge up the next attacker. Magcargo-GX would be used for the OHKO potential of Lava Flow (for enough Energy, you could KO anything, even a Pokémon VMAX), although the threat of Burning Magma GX was actually relevant in more situations than you’d expect, and would force the opponent to play conservatively with their resources, which is especially important against aggressive decks such as Mad Party.

In addition to them, Silvally-GX (Ultra Prism) deserves a mention. While it wasn’t played in the deck at its heyday, it was run in Mewtwo and Mew-GX decks in the short-lived Ultra Prism-Darkness Ablaze format at the POG Championships, and would definitely have been played in the post-rotation format hadn’t it rotated. Turbo Drive is a poor, but occasionally useful substitute to Turbo Strike, but more importantly, Rebel GX is a fantastic attack against Eternatus VMAX: it will OHKO it if the opponent Benches at least 7 Pokémon, which they’ll have to do in order to KO Mewtwo and Mew-GX.

However, these Pokémon are not indispensable to the deck. While few dared imagine a Mewtwo and Mew-GX deck without Solgaleo-GX, the truth is that the current format is focused on 2HKOs more than OHKOs: Pikachu and Zekrom-GX can’t use Electropower to reach higher damage ceilings, Blacephalon takes longer to get six Energy in hand without Fiery Flint, Zacian V tends to stick at 260 damage… therefore, your Energy stick around longer on the board. This means that accelerating Energy from the discard is not as important as it used to be, so Turbo Strike isn’t as important. In a similar vein, Lava Flow can’t be the focus of the deck. Without Turbo Strike, you can’t get as many Energy on board as before, so discarding them all in one turn to get a big KO wouldn’t be a viable move, especially against Pokémon VMAX that have more than 300 HP anyway.

So, Mewtwo and Mew-GX did of course get hurt by rotation, but every deck did and, perhaps more importantly, Mewtwo and Mew-GX wasn’t hurt as much as other decks. For example, it can still play Cherish Ball in addition to Quick Ball, which gives it a consistency edge over many decks in the format.

The new format also suits it because Mewtwo and Mew-GX plays more like an outsider. Many decks are focused on 2HKOs right now due to the high HP of popular attackers such as Eternatus VMAX, Centiskorch VMAX, and Inteleon VMAX. Therefore, decks don’t try to reach the highest amount of damage; for example, Vitality Band is rarely seen in Arceus and Dialga and Palkia-GX / Zacian V. Although it could fix the math and allow Zacian V to OHKO Mewtwo and Mew-GX, it would be useless in most other matchups because Zacian V can’t hope to OHKO a Pokémon VMAX anyway. Basically, the meta is focused on VMAX Pokémon more than Tag Team Pokémon, so having a bit less HP than them is not the end of the world. It’s true that 270 HP puts Mewtwo and Mew-GX in range of Eternatus VMAX, but on the other hand, it also has its own options to OHKO opponents. For example, any Pokémon hitting for medium damage can be punished with Darkest Tornado GX which can do hilarious amounts of overkill.

Since the meta is focused on Pokémon VMAX, most players are not trying to directly counter Mewtwo and Mew-GX. Cards like Mimikyu and Power Plant lose a lot of their strength when GX Pokémon start to play a secondary role, and that means that they’re only played by players who want to target Mewtwo and Mew-GX; this is very different from early last season, where Power Plant could be seen in all sorts of decks. Even Great Catcher is getting rare, which is good news for a deck that plays mostly Pokémon GX!

Finally, it’s worth mentioning that some cards that would give Mewtwo and Mew-GX trouble are not in the meta anymore, either directly due to rotation, or indirectly. A direct example is Metal Frying Pan. After Mewtwo and Mew-GX won the Oceania International Championships, pretty much all Arceus and Dialga and Palkia-GX / Zacian V (as well as other Zacian V variants) started to include this card to remove Zacian V’s Fire weakness which could easily be exploited by Victini V (and Reshiram and Charizard-GX to a lesser extent). However, now that it’s gone, Zacian V can’t lose its weakness and Victini V is once again a fantastic attacker against it. Zacian V / Lucario and Melmetal-GX decks are starting to include high counts of Weakness Guard Energy instead, but Arceus and Dialga and Palkia-GX / Zacian V, the more common variant, can’t afford it.

For an indirect example, see Dragapult VMAX. This card has been pushed out of the metagame due to the rise of Eternatus VMAX, the current BDIF. Dragapult VMAX is also much less impressive without Mysterious Treasure, Malamar, or Escape Board. That’s one of Mewtwo and Mew-GX’s biggest concerns gone, and it is definitely one of the factors leading to its current status.

In short, there is nothing in the current metagame that really prevents Mewtwo and Mew-GX from existing. The main concern for the deck is Energy management, due to the lack of Turbo Strike. This is why we have to build the deck with this in mind, and focus on attacks (including GX attacks) that do a lot for a low amount of Energy rather than powerful attacks that require more like Magcargo-GX’s Lava Flow.

Building the Deck


This concludes the public portion of this article.

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