UNION ARENA: Keyword Abilities, Ranked

In UNION ARENA (like a lot of trading card games), characters use common keyword abilities that exist across many different cards yet always mean the same thing. These keyword abilities unique to character cards help balance the game while also providing a common set of rules that work across multiple different strategies, decks and mechanics.

But what are the different keyword abilities in UNION ARENA, why do they matter, and which is strongest?

To answer this question, we’ll be looking at each and every keyword ability and ranking them from strong to strongest.

#7 Double Block

Double Block is a keyword that sounds better than it is. Theoretically it would be great to be able to block multiple attacks while defending. Perhaps exactly because of how good that would be, not a single character with more than 4000 BP has been given the keyword to date. So what does that mean? That essentially Double Block is only reliable for stopping attacks from low BP characters – characters that you probably already had the resources to stop, anyways.

And in all reality, most Double Block characters have less than even 4000 BP. Now, if we some day get a character with 4500+ BP also with Double Block, that could change this ranking substantially. In the meantime, Double Block ends up squarely on the bottom of this list as most of the time to really get anything out of it you’ll also need to hit an active trigger to stop meaningful assaults – a combo that is just too hard to pull off to be useful in most decks.

#6 Step

The next keyword ability on the hierarchy is also a significant “step” up from the last one (pardon the pun). Step is a very handy keyword depending on the strategy you are using. However, how useful it is largely depends on the deck that you are piloting.

High energy decks get a lot out of characters with step as they enable them to play more aggressively without having to worry so much about having energy the following turn.

Many different kinds of characters can have step, but most often it is found on support characters. The three-cost Alice pictured above is one of the strongest Step characters in the game, as she really lets you take full advantage of the keyword in a way most other characters can’t.

Because Alice has two-energy gen and also is a Raid target for her deck, you have a huge incentive to keep her on the energy line. Meanwhile, her “During Your Turn” effect sees her boost to a 4000 BP character if you have Kirito and Eugeo on your field. This also makes her a very solid attacker, and having step lets you strategically switch between the two roles however you need.

That being said, most other “Step” characters aren’t nearly this strategic, and many decks really have no need for them, putting this keyword towards the bottom of the list.

#5 Nullify Impact

Nullify Impact is a keyword that’s been getting a significant amount of attention ever since Volume 2 sets hit the shelves back in the middle of 2025. Whereas originally this keyword was largely present in zero-cost characters that presented a significant challenge in working into your deck strategy, now the keyword is available on a much broader range of characters that fit more easily into your strategy.

One of the strongest Nullify Impact characters right now is the three-cost Kenshin character who shows what a perfectly integrated Nullify Impact character can look like — very much like Alice from Sword Art Online exemplifies a character with step.

Nullify Impact works best as a keyword when it’s on a character that you want to fit into your deck anyways outside of it being a Nullify Impact. That’s largely because Nullify Impact isn’t quite strong enough of a keyword to work into your deck for that reason alone. When it’s present on a character with plenty of other strengths, however, it suddenly becomes a very attractive ability indeed.

Kenshin embodies this perfectly thanks to containing the color trigger, while also being very strong in his own right by switching to active the turn he is played alongside 4000 BP.

Impact is such an overwhelmingly powerful and present keyword in UNION ARENA (more on that in a bit) that having Nullify Impact is a very big nice-to-have. However, it’s still a circumstantial, defensive keyword that is not impossible to work around, meaning it works best when paired with other strong attributes in a card.

#4 Snipe

It feels a little weird putting Snipe this low down on the list because of how much I love this particular keyword. Perhaps more than any other keyword ability in UNION ARENA, Snipe gives you the most control over the board. Typically gaining Snipe means enabling you to choose which character your opponent will lose. Thanks to this, it acts as a form of removal in addition to a strong offensive play, and as if that weren’t enough it’s one of the few tools at your disposal that can’t be stopped by abilities that prevent you from choosing a character.

However, there are a few caveats to snipe that make it a little less effective. For starters, in order to be really, really strong Snipe typically needs to be paired with Impact, this way you aren’t just removing characters but taking a life at the same time. Without the Impact, Snipe is considerably less desirable as forcing your opponent to either take a life or force a block is just as good.

Additionally, because of the strength of Snipe, most characters have pretty strict paramaters around when it can be used. That will typically be in the form of a “When Played” effect that only lasts for the turn or some other gimmick that makes it harder to access, such as Sinon’s effect that only lets her gain Snipe when you are at four life or less.

When Snipe is paired with Impact and a strong attacker like Saito, however, it becomes one of the strongest combos in the game.

#3 Damage 2

Damage 2 is a very popular offensive keyword with many decks basing their entire strategy around it. Two decks stand out in particular for their love of Damage 2 – BLEACH Purple Renji Rush and Green Lancelot. Damage 2 is such a strong keyword that relatively few characters possess the keyword natively, and most have to fulfill some other requirement (such as paying an added AP) to access it.

Still, in many cases Damage 2 is scary enough for your opponent that they’d rather sacrifice a character than take such a hard hit. It’s at its strongest when there are multiple Damage 2 characters on the field at once. And when this keyword comes paired with Impact, then that card often ends up in the top tier.

#2 Double Attack

Of all the keyword abilities on this list, Damage 2 and Double Attack are the hardest to rank as they are very similar in essence although they differ drastically in effect. While Damage 2 is undoubtedly deadly, it’s at its strongest when paired with Impact. Meanwhile, Double Attack is almost always deadly, regardless of the character that has it. Of course, the stronger the character with Double Attack the more deadly, and some incredibly powerful characters even have Double Attack with Impact, making for powerful end of game closers.

Although Damage 2 is a scary thing to face down, unless your opponent manages to get it going into a direct attack it can often be stopped or shut down by sacrificing a chump blocker. Meanwhile, a 4000 BP character with Double Attack is never fun to deal with, often forcing your opponent to sacrifice a character to stop it and also take a life to boot.

It’s got a subtle advantage over Damage 2, but it’s still there.

#1 Impact

Impact is such a universal keyword ability in UNION ARENA that it almost feels cliche to put it at number one. But there’s a reason it’s so unniversal – it really is the single strongest keyword ability in the entire game. It’s so necessary in fact that virtually every top tier deck has an offensive character with Impact.

At the same time, a lot of the time Impact feels like a keyword that doesn’t really matter. And that’s the thing – it doesn’t matter until it does. Sure, you’ll happily take that Impact attack early on in the game when your life is full and you’ve got nothing left to lose. But allow your opponent to fill up their board with more than one Impacter and let the game go a few more turns – suddenly you’ll be shaking in your boots for how unable you are to do anything about the offensive.

Indeed, Impact is so strong that it’s the only keyword ability in the entire game that has another keyword ability just to counter it alone! There’s a reason Nullify Impact is rapidly becoming a mainstay in most competitive decks, and that’s because of how strong this particular keyword is.

And while the rest of the keywords on this list are good some to most of the time depending on the situation, Impact is never bad to have around. Combine it with any of the other keywords (as it often is) and suddenly you’re in a lot of trouble.