Dimir, the guild closest to my heart, is one of the trickiest ones to design for. It often gets the short end of the stick when it comes to guild mechanics and rarely nowadays, gets to be the best deck in any given Limited format. As you'll see below, Dimir's peaks tend to be well spread out. Still, it does come up from time to time, so here are three times that was the case.

Kamigawa: Neon Dynasty

Straight away, we're going back three years from time of writing to find the most recent example of Blue-Black being the best deck in Limited. Is it a coincidence that this format is remembered so fondly? Probably. Still, starting at the top of the rarity chart, Blue and Black both got some sweet ones. Inventive Iteration was a great card, regardless of whether you had artifacts to synergise with its second chapter. Tatsunari, Toad Rider is similar in the sense that it's great if you have a few enchantments in your hand, but it's still very good even without them. Dimir also happened to get two of the better entries in the legendary dragon cycle. Junji, the Midnight Sky was statistically the best of the bunch, but Kairi, the Swirling Sky, is less than 1% win rate behind.

Then we get to the non-rare cards and things start to make even more sense. Life of Toshiro Umezawa is better than most rares. It's just so flexible and the creature it leaves behind is a relevant game piece. But really, Blue-Black's biggest strength was its synergy. The ninjas in the set worked well together, while several of them were just good cards at face value as well. Virus Beetle might have been the best Ravenous Rats of all time thanks to all the nijutusu shenanigans. Even innocuous looking cards like Network Disruptor played out very well, accruing tiny advantages at minimal cost.

War of the Spark

Another three years back brings us to War of the Spark - a more divisive set, to be sure. Not everybody liked having planeswalkers all over the place, but it was a good time to be a Dimir player. This was especially true if you happened to open Liliana, Dreadhorde General. Not only was this the best card in the set, it is the fourth-best Limited card in the history of 17lands, based on win rate. If you switch to "drawn turn 1 or later," it shoots up to 72.8% so clearly this card was not messing around.

But Dimir also got to play with Enter the God-Eternals, which couldn't really be played in any other decks. You could try and splash it, maybe, but you had to be base-Blue, realistically, and the colourless fixing in the set was not great. Then there was Finale of Eternity, which was another game-ending bomb. If you ever got to resolve this for 10 or more, it was basically impossible to lose.

As always, it's important to talk about the non-rare cards in the set. Here, too, Blue dominates. Tyrant's Scorn being a flexible removal spell was the best uncommon in the format. It is surrounded at the top of the win rate list by the likes of Eternal Skylord and, surprisingly, Augur of Bolas. I guess if you're putting the 1/3 into a deck full of removal to keep you alive while you wait to draw your bombs, it's pretty good.

Finally, one of the things that helped to make Dimir's bombs so format-warping is the fact that the traditional aggressive colour pairs were not doing so well. Boros was the weakest two-colour deck in the format, not helped by the fact that it had to deal with planeswalkers buffering opponent life totals in most games. Dimir needed time to cast its bombs, and the format enabled that very nicely.

Rivals of Ixalan

All the way back in 2018, Rivals of Ixalan was a current set when MTG Arena was first released. It's a fascinating set to think about in that context, because it came off the back of one of the most disliked draft formats of all time. Rivals somewhat improved on regular Ixalan, but not by much. It was also the last set to have a small expansion, so there's a lot going on here.

Speaking of a lot going on, Black was unbelievable in this set. Orzhov was the second-best color pair to be in, thanks to some strong vampire typal synergies, but Dimir was the daddy. Tetzimoc, Primal Death was a messed up card, and putting it in a set with Recover was certainly a choice. Then there's Tetzimoc's little cousin Ravenous Chupacabra - an uncommon that was statistically the third-best card in the entire set, with an absurd 66.6% win rate when drawn.

The fascinating thing about all of this is that, because Rivals was drafted alongside Ixalan, those Rivals cards were working overtime. We don't have 17 lands data for original Ixalan, but Blue-Black was not a colour combination that felt particularly strong at the time. It had some good rares, but removal was expensive and/or conditional, which is not a great place to be when the format is dominated by aggressive tribal decks. Dimir theoretically had pirate synergy, but it was nowhere near as strong as Izzet in that regard. Basically, the Dimir cards in Rivals were so good that they were still able to shine despite being dragged down by the state of the previous set.