Slitherwisp Art by Yigit Koroglu

Dimir Flash: Applied Theorycrafting in Best-Of-One

Ikoria: Lair of Behemoths is here! And with it comes a brand new best-of-one metagame environment chock full of chaos! What deck will emerge as the deck to beat? Will Red Deck Wins hold onto its crown? Will Companions break the format? How will Mutate transform things? Who killed JR? We’re one week in and a few decks have emerged at the top of the heap, with Companion being very much a format definer in the early going.

A hot deck very early on has been Dimir Flash, which takes an entirely different approach from Dimir Control. There are a few counterspells and a few Mutate creatures, but for the most part this is a midrangey deck that creates value and casts creatures opportunistically; every creature in our early build has Flash to facilitate this. It’s been a lot of fun to play, along with being a 55% win rate deck in this highly unstable environment.

A few notes upfront:

  1. This is a deck with a lot of new Ikoria cards and most of them are rares or mythics. If you’re someone who runs light on wildcards, it is generally good advice to wait for the metagame to settle before diving in with the WCs.
  2. One of the reasons Simic Flash suffers in the current metagame is due to the heavy presence of Teferi. Best of One has fewer control type decks so I think there’s a lot more opportunity in this format than in Traditional, but Teferi is still a problem to be considered. This build maintains more creatures for killing off our favorite planeswalker, so I think the impact is manageable, but it’s something to keep in mind.

Dimir Flash is new to the current Standard environment, so it may have unfamiliar play patterns for some Arena players. Fortunately, it is very similar to Simic Flash which has been less relevant in Standard for a while but has still been around. If you’ve played that deck, then Dimir Flash will be a fairly simple adaptation.

Simic Flash is a deck I think we’ll see some of in this environment as well, and while Simic Flash has Nightpack Ambusher and Frilled Mystic to go with Uro and Growth Spiral, it’s a deck that struggled to establish itself as a force in Standard over the last several months. Dimir Flash has, in my opinion, more synergy than Simic does with how Nightbonder and Slitherwisp tighten up mana costs and create card advantage. A Sultai Flash merger of the two is all but inevitable and may be the ultimate winner in this sibling rivalry. For now, Dimir appears to be the hot hand. The ultimate winner will be whichever deck can put the likes of RDW and, more importantly the sacrifice decks, back on their heels. Maybe that will be none of them, time will tell!

Deck Building in Best-Of-One

This metagame is still extremely young and more open than Best of One has been in quite a while, since Red Deck Wins got few if any new pieces to add to its repertoire. Whether it is still strong enough to remain the dominant deck in the format is too soon to say, but I expect not. I think it will continue to be a heavily present deck, but its aggregate level of success (it was Tier 0 in Bo1 the last three months in my opinion) and power is going to drop. I expect it to be a T2 deck. Still, the general strength of Aggro in Bo1 remains. The impact of the hand smoothing algorithm remains as well, and the absence of a sideboard for most decks are also factors to continue to consider in Bo1 deckbuilding and play.

This is a deck that, when played well, is going to cast few, if any, spells on your own turn. The Flash ability on all of the creatures allows you to cast them at the end of your opponent’s turn, so they can’t be sure what you’ll have in play on your turn and will be uncertain how to prepare for it during theirs. When they declare an attack, they won’t know if you have just the creatures in play available or if you’ll be able to drop something larger in their path. This approach also allows you to hold your mana open for countermagic (or simply the threat of countermagic) and blunts their ability to deal with threats through sorceries. 

Decklist and Card Choices

BO1 Dimir Flash by Red5ive – April 2020 Season

[sd_deck deck=”c6Dw-16Kt”]

This is a deck with a ton of synergy. A full 20 spells are new inclusions from Ikoria, and those are the ones I’m going to focus on. Depending on how aggressive you want to be, which may depend heavily on what deck you see your opponent roll out, an ideal opening for this deck may be to drop a Spectral Sailor at the end of your opponent’s first turn, then Mutate it with a Sea-Dasher Octopus on top when you attack on your second turn for damage and card draw. Holding onto the Octopus until the end of your opponent’s next turn may be the better approach in other cases. Or you could go with Cunning Nightbonder at the end of the opponent’s turn, keeping mana open to disrupt them with countermagic. Playing at instant speed really gives this deck a lot of flexibility, allowing it to make informed plays based on what your opponents are doing.


Slitherwisp is like The Dude’s rug; it really ties the room together. It’s going to be a huge target for Stomp, Shock and other spot removal with just two toughness, but this card is to Dimir Flash what Innkeeper is to Adventures decks. It’s also why I expect Dimir and Sultai Flash to be more prevalent than Simic.


Cunning Nightbonder is another card that ties this deck together marvelously; its ability to reduce Flashed Mutate costs makes it even better. Nightbonder doesn’t have the punch that Lucky Clover has for Adventures decks, but it’s one of the big pieces of why I think Dimir will come out ahead of Simic Flash.


Sea-Dasher Octopus is a card I love, particularly with its Mutate cost being cheaper than its base CMC; the ability to Mutate at instant speed is what really makes it shine though. There aren’t a lot of creatures in the deck you’ll want to turn into 2/2 creatures (it’s basically just Spectral Sailor, though I see some situational applications for Brazen Borrower as well), but being able to get card draw out of a creature that your opponent just decided not to block is a nice kick in the pants. If you do Mutate the Borrower into a 2/2, make sure you are mindful of the timing and the fact that it will only be able to block fliers. I had a boneheaded moment myself, in my first game with the deck, where I forgot it would retain that ability.


Voracious Greatshark is an expensive counterspell, but with the huge body that comes with it, Jaws is well worth the cost. Get out a Nightbonder or two and you’re chopping down the cost on your countermagic tidily and getting much more efficient value. The five toughness keeps Greatshark out of range of a number of sweepers, and in many cases this will be your finisher.


Dirge Bat is one card I am not completely sold on yet, in large part because its mutate cost is high and there aren’t a ton of other Mutate triggers in the deck, though it does make Sea-Dasher a much more dangerous card in the deck. Still, a 3/3 flier with Flash and the ability to act as conditional removal is pretty good, and it has gotten me out of a couple tight spots. Mutating a Spectral Sailor into a 3/3 and removing a creature or ‘walker makes for a nice little combat trick. Just don’t forget about Teferi lurking in the corner, stopping your Flash effects!

The rest of the deck should be familiar to any Blue midrange or control players; some countermagic and the value-rich Brazen Borrower fill this deck out. I thought about including Fae of Wishes for the ability to throw open the sideboard, but there is so much synergy in this deck as it is, it just didn’t fit to include an expensive sorcery.

Cards I didn’t include in this build are headlined by Tyrant’s Scorn; it’s a card I have seen in this decktype fairly frequently, but for now I’m content with the deck as it is. If you’re finding the metagame to be faster than you can handle, putting in a couple of those in favor of some Dirge Bats may be the way to go.

On the manabase side, I’m running a little on the lighter side than if this was for Traditional; I’d probably pull a Spectral Sailor for an Island in that format. I’ve seen some use of the Triome lands for Cycling purposes in other builds as well, but I’m not a fan of that approach in this particular build. If I did take that approach, I’d probably swap them in for Fabled Passages; the mana base in this deck is pretty reliable.


The metagame currently is still a bit of a mess in many levels of Bo1, there are folks clinging to old decks that don’t quite cut it anymore and others diving in to playing as many new cards as they can, and others playing more refined decks that may still need more tuning as the metagame shakes out. I’ll tell you straight out that I don’t expect this metagame to remain terribly stable, several of the Companions are, in my opinion, at risk of meeting with the ban hammer. It’s one thing to give players another card in their opening hand, it’s quite another to make that card so potent at creating further card advantage.

Mono Red Aggro

The King is dead, long live the king! RDW has dropped off a lot in the first week of this metagame due to its incredible weakness against Sacrifice, this matchup may not be one to worry about so much in the near future. Flash typically struggles against the likes of RDW, but I’ve found this deck to be surprisingly effective, both when I have been piloting Dimir and when I piloted RDW. Dropping blockers suddenly in front of attacking creatures and being able to counter their big threats really messes with the groove they are trying to plow through your life total. RDW will struggle to stop your fliers and the bounce ability from Brazen Borrower is key for timely removal.


Sacrifice is a brutal matchup, but one I have had some success against, at least in the early going by targeting key cards. There are a lot of flavors evolving in the Sacrifice realm; Rakdos, Orzhov, Jund, Mono Black and Mardu Sacrifice are all playable right now and the biggest one in the early meta are the Lurrus decks. I expect this to be the archetype to beat in Bo1 this season but there may be some shaking out of which is top dog. Early countermagic to stop Lurrus from ever hitting the battlefield is going to be essential. The Flash theme to the deck let’s you keep that mana open for the counterspells until the end of your opponent’s turn when you can drop a threat after you’ve held them off from playing anything that turn is really critical. If this fast deck becomes a dominant part of the metagame long term, then swapping Tyrant’s Scorn in place of the Dirge Bats will be a change to consider. I wonder if a Sultai Flash deck with Lurrus may be worth exploring, but that’s an article for another day.


Fires decks were in short supply in Bo1 in the first few days of the metagame but that has changed in a big way, unsurprisingly. Anything that plays Teferi is going to be a tougher matchup and, if Flash becomes a big thing in the meta, I expect Teferi to see even more play in Bo1 than it already has. Keruga fits into this deck almost seamlessly and is a threat that must be countered, meanwhile Yorion fits in with basically no downside. The control aspects of Dimir Flash can shift the balance against Fires if you can hit the right spells and get some card draw going on your side. Don’t let Fires or Keruga/Yorion hit play.

Temur Reclamation

Wilderness Reclamation decks have been a big chunk of the metagame early on. The big threat to watch for is Shark Typhoon. This absurdly named card is a monstrous creature engine in the Reclamation build. Keeping Reclamation from hitting the field has long been the key to stopping this deck, now it’s stopping Reclamation and Typhoon.


Gyruda decks have been a pretty large part of the early Bo1 metagame, with blink mechanics a common part of the deckbuild. This has been a matchup I like so far, if you can keep Gyruda off the field. Sensing a theme? Yes, countering those Companion cards is basically essential for this deck, and indeed in the current metagame in general. Gyruda into Spark Double and another creature on top of that is a real gut wrencher. On the plus side, most Gyruda decks don’t seem to be running much graveyard recursion. On the down side, they are generally running three more Gyruda in the main body of the deck.

Mono White

Mono-White is still running around a little with big lifegain and even bigger attacks. This hasn’t been a great matchup so far; it drops threats fast and builds them up to be unmanageable for Dimir to take out. There isn’t a great sweeper in the Dimir slice of the pie, which is what you really need against MWD. The hope hear is to be able to counter anything too dangerous, bounce the Ajani’s Pridemate types, and get the card draw engine going to go over their ability to gain life.


Control decks in general seem to have taken a backseat in this early meta, even more so than usual for Bo1. Any control that features Teferi will of course represent a challenge with a lot of these matchups will come down to who gets an engine for card draw going first. I like the matchup for Dimir in general though, especially with Nightbonder making your Flash creatures uncounterable.

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