Decks come, and decks go. The metagame has no sacred cows. A deck must find its niche and then hold it to maintain relevance. Strength in a vacuum doesn't matter, nor does the dedication of the player base. Three years ago, Grixis Death's Shadow was an absolute monster of a deck, to the point that some called for its banning. Today, the metagame has moved on, and GDS is Tier 3 at best. One might be dismissive and say that it's all survival of the fittest, but that's not necessarily true. Just ask Mono-Green Tron, a deck that has fluctuated between Tier 1 and unplayable over the years. Relevance is relative, and so long as they inhabit a valid niche, a Modern deck is never truly gone.
Which is an elaborate way of introducing the fact that for the first time in years, I'm going to discuss Merfolk today. While I've always thought the deck was underrated, I had to admit that Spirits and Humans were doing Merfolk's thing a lot better, and set my baby aside. However, everything changes, and due to a quirk of the current metagame, Merfolk is better positioned than it has been in years. Whether this translates into a more permanent role in Modern remains to be seen, but the current version is a textbook example of correct metagaming and positioning. And much better than other so-called metagame solutions.
Whenever I hear chatter about a deck's return, I'm always skeptical. Modern is very much an enthusiast format, and players like to play their deck. This is a good thing, as Modern also rewards mastery of your deck. However, I'm not so blind as to think that means that any deck is actually good. Because I used to fall for that very trap. I've played Merfolk in the face of some very broken decks out of a combination of stubbornness and genuine belief in its potential. And I was mostly let down. I thought I was out for good. And then I saw something that drew me back in.
Merfolk hasn't been completely absent from Modern since I stopped playing it. However, it's never put up decent results or had much of a metagame impact. This is despite some aggressive printings in Ixalan. Yes, it does often appear in League data, but that means nothing; anything can go 5-0 in a League. The bottom line was always that the deck has a very strong linear attack, but without the disruption of Humans, Merfolk struggled to hang with the combo and control decks. What piques my interest now is that MissTrigger won a Challenge---the whole thing. That's a strong signal of quality, and worth looking into.
I've Got History; Also, Bias
I will admit that at least part of this is simply that I'm me. I've been playing Merfolk a long time. It very convincingly won me the PTQ that took me to my only Pro Tour. I had lots of solid results with the deck over the years. And I was always playing UW and extolling the virtues of the deck in the face of everyone else jamming mono-blue. To see my pet deck getting results is certainly going to draw my eye more than most.
It also means that I understand what the deck is going for and why it worked. And the fact that MissTrigger won that Challenge is no accident. Merfolk, particularly that version of Merfolk, was expertly positioned for a field well represented by the Top 32. Whenever the format moves towards slow blue decks, I expect Merfolk to see more play thanks to islandwalk. However, MissTrigger's version was prepared for a field of not only UWx decks but Prowess, Eldrazi, and Ponza. The only question is how they got past all the Toolbox decks.
The metagame is dominated by (in order) Prowess, Eldrazi Tron, and GRx midrange decks. Stoneblade is up there, too. Given that Humans has always been strong against Eldrazi and taxing effects are strong against velocity decks, I thought I'd be shouting about the virtues of Humans in this meta. That isn't happening, and the problem is Prowess.
Simply put, Thalia, Guardian of Thraben isn't good in that matchup. The problem is not that taxing effects aren't good against Prowess. They are. The problem is that Thalia is too fragile. Prowess universally runs Lava Dart maindeck, and most have a few Gut Shots between maindeck and sideboard. A turn two Thalia is barely a speed bump, and without that delay, Humans struggles to keep up. In fact, most Humans die to a single Dart hit, and there's not much Humans can do about that.
Doing the Right Thing...
And this is the first place that Merfolk shines. Unlike Humans, the vast majority of Merfolk's creatures have 2 toughness. Thus, Dart's effectiveness is muted from the get go. Then, MissTrigger replaces Thalia with Unsettled Mariner. Mariner is generally much weaker than Thalia since it only taxes spells that target. However, that is almost everything in typical Prowess decks. Coupled with the above mentioned resistance to Dart, Mariner is far more effective and breaking up the big Prowess turns than Thalia.
...With the Right Tools
The next critical adaptation is relevant interaction. Humans has getting enormous and Reflector Mage as maindeck answers for creatures. Merfolk can also get big, though lords are more fragile than counters. There is the advantage that Prowess has islands and does a lot of damage to itself, but that's minor compared to Merfolk's other advantages. See, Mage is very good, but it costs three. And Noble Hierarch only lives past the first turn in games Humans is never going to lose against Prowess. Thus, Mage is too slow most of the time.
Merfolk has more interaction, but it's also all the right interaction for the matchup. Merfolk vs Prowess is very much about tempo, and the interactive Merfolk creatures offer far stronger tempo plays. Back when I played Merfolk, I was always skeptical of Harbinger of the Tides. It was a good card, but the old metagame was more about attrition or combo than racing, meaning Harbinger was mediocre. Prowess is another story. Tapping Stormwing Entity with Merfolk Trickster or bouncing it during combat with Harbinger is a huge swing. There's the tempo of getting a your creature down and bouncing theirs, but there's also card advantage, since Prowess pumps so many spells into its creatures. They're actual spells, not cantrips, so Prowess does run out of gas. Plus, the Merfolk also only cost two, so they'll see play early enough to make a difference.
Bring a Spare
Finally, there's the sideboard. Chalice of the Void is obviously huge game against a deck that's mostly one-mana spells. It's the main reason that Eldrazi Tron's been relevant so long. Add to this Merfolk not playing many one-mana spells, and it's a huge beating. And Chalice is also good elsewhere.
However, the real genius is running Tidebinder Mage. I also never ran Mage back in the day because Jund doesn't care if it can't block for a turn and Elves just hemorrhaged too much stuff for icing one creature to matter. But against Prowess, Mage becomes a Time Walk. Prowess must kill Mage the turn it's played, or they lose an entire turn killing the Mage, and not attacking. And doing anything on the opponent's turn is bad because it gives up prowess triggers. Trickster can fog a single attack, but Mage represents multiple combats lost and can attack itself. Merfolk thus has the right tools to really kick Prowess around.
However, if the only criteria to being a good deck was a strong matchup against the top deck, then Soul Sisters would see more play. Modern is too broad and diverse to target the top deck and achieve success. Fortunately, Merfolk has a number of strong matchups, many of which are top decks right now. Merfolk has always been decent to very good against Eldrazi decks: you just swamp the board and swim past because Chalice is too slow and Merfolk plays Cavern of Souls. Blue decks, particularly ones without sweepers are similarly good. That Merfolk is good against Ponza was a real surprise to me.
Ponza is an accelerated beatdown deck. Its creatures are enormous, and it has plenty of removal between Bolt, Bonecrusher Giant // Stomp, Glorybringer, and Chandra, Torch of Defiance. The mana from Utopia Sprawl and Arbor Elf let this ostensibly midrange deck play more like an aggro deck and just outmuscle Merfolk... in theory. But there's a reason we play the game, and it turns out that the matchup is a lot better than I thought.
See, without that acceleration, Ponza just starts clunking. And Merfolk uniquely attacks Ponza's mana. Dismember on Elf is obvious, but the real killer is Spreading Seas. Sprawl is an "enchant forest" card, and should Seas flood that forest, Sprawl falls off. Thus, Merfolk can attack both parts of Ponza's main advantage while largely ignoring Blood Moon. This makes Ponza play more like its older, and far worse, incarnations, which were good matchups back in the day. It's hardly a cake walk especially after board, but much better than expected.
That Pernicious Metagame Deck
Ultimately, that's the key to a good metagame deck. You have to hit the deck you're targeting without losing sight of the rest of the metagame. Not only that, a metagame deck needs to be reasonable on its own within the Modern ecosystem. Again, Modern is too diverse to really target a single deck, and if a deck's gameplan is only good against a single type of deck (or just one specific deck), it is doomed to fail.
I've warned against trying to metagame a lot. The problem is that players tend to tunnel vision on one aspect of the format and forget about the rest. On top of that, they often fixate on specific interactions that they think are good and miss the wider context. Or worse, they miss the actual reason that a deck or interaction is good, and miss their target. MissTrigger's deck is a case study in how to do it right: have a generally good gameplan; hit the right things about the deck(s) you're targeting; hit other good decks too; and most critically, don't play into the gameplan of the deck you're targeting. They wanted to live in that world for a reason; do you really think you can come into their house and do it better?
The worst offender for this is BW Tokens. Practically since the dawn of Modern, players have tried to make the deck work, and it hasn't ever been a metagame force. Or even worth considering. Every few years, I see it getting attention as a metagame deck and it's frequently called a Jund killer. The argument is that Jund can't win an attrition fight against a token deck. Jund has to trade a full card of removal for a token, which is only part of a card. The sheer volume of tokens then overwhelms Jund while discard rips up Jund's hand. After all, Lingering Souls is a major reason that Junk is favored over Jund, so more of that is better. Right?
The answer is a flat no. The reason that Souls is good against Jund is that it mutes Liliana of the Veil. Discarding Souls to Liliana is still positive value, and the tokens provide ablative armor against her downtick. Thus, Junk dodged Jund's best card while getting full value from its Liliana. It wasn't the tokens but their context that mattered. Yes, trading a Bolt for a Spirit token is poor value. However, that doesn't make it no value. It also ignores that the tokens are 1/1s facing huge Tarmogoyfs and Scavenging Oozes.
When Jund was big at my LGS back in 2015-2016, I made BW tokens and was continually disappointed by how mediocre my Jund matchup was. Unless I hit my planeswalkers, my tokens could not race any reasonable board state. My creatures were too small, and if I had to start blocking, I probably couldn't stop. And that's not mentioning the impact of sideboard sweepers. Worse, discard was very good against tokens. The underpowered discard deck fighting a powerful discard deck is disadvantaged.
...But Flawed in Reality
Which is a lengthy set-up to me warning against playing the Mono-White Tokens deck that appeared at the end of July.
This deck is touted as a new and potent metagame deck. The idea is to race Prowess by chumping while beating in the air, especially now that Crash Through sees little play, while going wide and tall with all the anthem effects against everything else. After testing it myself (and watching a lot of Youtube while researching this article), I've come to realize that it's fallen into the same pitfalls as the old BW deck.
The token makers all cost a lot of mana. There's no acceleration, just various ways to pump the tokens. Thus, its speed is more like that of a beatdown deck. When it all comes together and the tokens get a few pumps, the deck looks good. But Force of Virtue is hard to use, Venerated Loxodon is not good tempo, and when tokens starts to fall behind, it stays behind. There's no reset buttons or other ways to catch up; you just make more tokens and hope. Thus, as the linked Jim Davis video shows, Tokens is great at snowballing, but if a single thread comes loose, the whole sweater shreds. He didn't even beat Prowess because, again, Dart is great against x/1s.
The Lesson of Good Metagaming
Metagaming is hard. It's really easy to fall into a trap and miss the subtleties of a deck or a particular matchup and focus on the wrong thing. The new tokens deck is making the same mistakes as the old tokens deck in thinking that going wide with 1/1s is enough to beat attrition decks. It isn't, and never has been. Token decks snowball well, but the ball breaks apart easily, and catching up is very hard. The mono-white version has an advantage in that it can get explosive with anthem effects, but that doesn't excuse the underlying weakness of needing to draw the right cards in the right order.
Be more like MissTrigger and have a good gameplan that targets the right parts of the matchup. I don't know if Merfolk is going to remain a force in Modern, but as long as the metagame remains as it is, there is a chance.