Fullmetal Alchemist is a highly anticipated UNION ARENA set launching everywhere on July 25, 2025. Based on the immensely popular anime, in this set players will find intriguing strategies that let them live out the powerful combos found between brothers, battle for their life at Fort Briggs, or even summon the deadly Father character to devestate the board. There’s truly a broad range of options available to you in the Fullmetal Alchemist set, delivering a well-rounded range of decks that while not the strongest in the game, can certainly hold their own in the UNION ARENA meta.

Which Fullmetal Alchemist deck is strongest? Below I’ll be ranking them from strong to strongest, staring with the Blue Armstong deck.

#6 Blue Armstrong Deck

Starting off this list with Blue Armstrong shows how well-rounded FMA is – this deck is by no means a horrible deck yet still manages to be weakest in the set. If you’re familiar with the Rukia BLEACH deck, this one is similar in that it seeks to reward players for fielding two-AP characters. The deck’s strongest card may be Olivier Armstrong, but its when you combine her with her brother and even Buccaneer that the deck really starts to shine. An especially interesting card in this deck’s repetoire is the Fort Briggs site, one that reduces the AP cost of a Briggs character you play this turn, effectively acting like a free Final trigger card.

The strongest Armstrong combo outside of reducing AP costs for cards played, however, is to switch your heavy hitters to active the turn they are played or even after they attack – something Olivier excels at.

Blue FMA is a great deck for players who enjoy the raidless style of deck in UNION ARENA: one that focuses more on offense through punishing attacks than through tricky combos or strategic removal.

#5 Yellow Xing Deck

The Xing affinity deck is all about stacking up energy in order to unlock some pretty handy effects. While you have plenty of two-energy generating characters to help reach this lofty threshold, your strongest is the three-cost May Shang.

Raid May onto the Energy Line and she becomes a three energy generating character, while also letting you draw a card. Having her handy in your deck means having a pretty solid chance at reaching the seven-energy threshold. However, that brings us to the main negative point about this deck: does the payoff equate the setup required to get these abilities off?

Well…not exactly. Unlike other decks like Lancelot or GGO that unlock powerful effects capable of sidelining characters or attacking with enhanced damage or even Impact, the Xing deck is more about granting you utility, like the ability to not be able to be blocked by 4000 BP characters or more.

Scar, meanwhile, does hit a little harder once you get to seven energy. But even he does little more than swing for Impact at 5000 BP. Oddly enough, this deck’s strongest character, Greed, doesn’t have anything to do with the seven-energy-or-more mechanic that defines this deck.

Greed forces a block but does so without the advantage of Impact the way the stronger Guren from Purple Code Geass does. Meanwhile, he does have a handy “When Sidelined” effect, but that’s not enough to make him the strongest card we’ve ever seen, and his effectiveness is further diminished by his relatively high energy-cost.

Ultimately, other decks in Fullmetal Alchemist are capable of doing a lot more for a lot less.

#4 Purple King Bradley Deck

If you’re looking for an aggressive deck with plenty of removal and some additional power, King Bradley looks like a pretty solid option. While it’s higher energy cost makes it a bit less versatile than some of the other options available in FMA, it makes up for that with some pretty solid effects, like Kiblee’s removal (combined with BP reducing effects to make it go farther) and King Bradley’s Double Attack at 5000 BP.

For all that, this deck’s strongest play might just be the three-cost Pride with the Color Trigger. While you could feasibly include this guy in the more Father-focused Homunculi deck, Lust just feels so strong in that strategy it feels like he might be a little bit of a waste. However, his effect that lets you sideline your own cards certainly works well into an endgame card like Father that needs 20 cards in sideline in order to use.

Also boosting to a 5000 BP character with Impact 1 and at only a three cost is pretty incredible in its own right, giving you a serious competitive edge for any part of the game.

Father feels like a peripheral character in this deck. You won’t be sidelining a ton, but there likely will be chances to play him straight from your sideline later in the game when you’ve amassed plenty of cards in the sideline.

#3 Blue Mustang

Blue Mustang is FMA’s pure removal deck. This deck is very straightforward – essentially Purple BLEACH but where you discard cards to remove characters instead of using your sideline. Essentially, you get to sideline a character with 1000 BP or less using his When Attacking. Of course, that’s not going to get you very far. Luckily, Mustang also lets you discard cards, and add 1000 BP to the range of your effect for each card discarded. What’s more, you can discard yet another card after the character is sidelined in order to send it to the removal area, thereby thwarting decks like Yellow Eric Bros or the Purple Father deck.

To make things a little easier for you, you have plenty of effects that lower the BP of characters on your opponent’s field, putting them much more easily in range of Mustang’s effect. The strongest of these is going to be your Hawkeye Raid. She can neg opposing characters by as much as 2000 BP in the right scenario.

As far as removal decks go, Mustang is pretty second tier. It won’t be nearly as consistent as the best removal decks out there like Purple Code Geass or BLEACH, but should still be a fun option especially for the many Mustang fans out there.

#2 Purple Father deck

Personally, I’m very excited about this one. The Purple Homunculus deck has all the trappings of a powerful, high end deck. If you are looking for a comparison to an existing deck in the English meta, the closest thing is Muzan from Demon Slayer. However, unlike that deck, this one appears at first glance to have all the tools you need to actually compete well into the meta. Here’s why:

Plenty of strong triggers.
Solid Raid attackers.
Father comes in active.

Of all the attackers, Lust feels strongest, and really acts as the backbone of the deck.

Playing her alone will quickly fuel your sideline and make it much easier for you to reach that 20 cards in sideline. She’s not the only tool at your disposal: you also have Nina & Alexander, Homunculi and more. But she is your strongest. Manage to quickly fuel your sideline and you can take advantage of your powerhouse Father character.

Father is just crazy strong. When Played he’s sidelining an opposing character, and then has a permanent Double Attack keyword. Coming in active makes him much more feasible to play under pressure. Meanwhile, his activate main from the sideline means you can always have him handy when you reach your 20 cards in sideline number, as long as you have three cards in hand.

This deck feels like a huge upgrade from the Demon Slayer Muzan deck, and players who love the late game powerhouse decks are sure to go crazy for this one.

#1 Yellow Elric Brothers

Yellow not only looks strong – it looks like a ton of fun to play. As far as UNION ARENA decks go, Yellow FMA falls into the buddy-deck category: those decks that unlock their full effects through the interoperability between two or three named characters. Examples of other buddy decks are Integrity Knights, Yellow Tanjiro, etc.

In this deck, we see the focus placed on the two brothers. Just like how in the show Edward and Alphonse battle their way through countless foes, in UNION ARENA they’ll be teaming up to battle it out in a highly competitive field.

Apart from that general idea, there are some very unique and interesting plays here, especially around playing characters via effects. Take “Let’s Go Home” for example.

Play this card and it not only brings back a character from your sideline, you can then play that character for no added AP. Suddenly your entire sideline becomes a resources for you to pull from at will. But it gets even better. Chain this card with three-cost Alphonse and you keep the combo going by drawing an extra card.

Of course, your strongest character for playing your Alphonse characters for free is actually your four-cost Edward. While you can easily use his “When Played” to play three-cost Alphonse, if you have your “Gateway of Truth” on the field, you can also use him to play your even stronger four-cost Alphonse. Manage to pull that off and you get access to a host of powerful effects, including setting Alphonse to active and resting an opposing character.

Yellow is a powerful combo deck capable of doing a lot of damage quickly. As far as the Fullmetal Alchemist decks go, Yellow feels the strongest and most consistent of them all, and will likely show up at many, many store tournaments and Rare Battles in top spots.

UNION ARENA: Every Fullmetal Alchemist Deck, Ranked