Commander Showdown — Mairsil vs Experiment Kraj

Some Assembly Required

Magic: the Gathering is filled to the brim with abilities. We have triggered abilities, as seen on cards like Eternal Witness and Phyrexian Arena. There are mana abilities, famously found on lands, artifacts, and mana dorks such as Gilded Lotus and Llanowar Elves. Then we have static abilities, like the classic Glorious Anthem or Grand Abolisher.

Lastly, we have activated abilities. These are easily identifiable, since they are always written as “[Cost]: [Effect.]” From Royal Assassin to Ant Queen to Glare of Subdual, activated abilities play an enormous role in the game, and there are no two commanders that better explore the complexities and intricacies of activated abilities than Mairsil, the Pretender and Experiment Kraj.

Both of these commanders accumulate the activated abilities of other permanents, one through the use of cages, the other through the use of cytoplasm. Mairsil can capture any creature or artifact from your hand or graveyard, giving him a wide diversity of effects to steal. However, he can only use their abilities once per turn. The Kraj has no once-per-turn restriction, but its ability is limited to creatures.

How do these differences affect their strategies and card choices? If you’re looking to build a deck that mixes and matches abilities, which commander is right for you? It’s time for Commander Showdown: Activated Ability Edition.

Project Kraj

I’ll start with Experiment Kraj, the Simic monstrosity that absorbs the abilities of each creature with a +1/+1 counter. (Note: not just your creatures, but any creature!) To get the ball rolling, Kraj can also tap itself to distribute +1/+1 counters. This Ooze Mutant was actually Momir Vig, Simic Visionary’s secret project, and it literally ate Rakdos the Defiler, so you know the Simic don’t mess around.

Before I go any further, I want to explain a rules interaction newer players may not know. Every Magic card refers to itself in the third person. For example, “When Festering Goblin dies, target creature gets -1/-1 until end of turn.” Whenever a card says its own name, it just means “this card.” Festering Goblin won’t trigger when another Festering Goblin dies. It only refers to itself.

This is important because Experiment Kraj will absorb abilities of creatures that refer to their own names. The classic example is Simic Ragworm, whose ability says, “Untap Simic Ragworm.” In my youth, I made the mistake of thinking that if Kraj put a counter on the Worm, it would therefore gain that ability precisely as worded: “Untap Simic Ragworm.” Thankfully, this is not the case. When Kraj gains an ability, it uses its own name. Thus, if Simic Ragworm has a +1/+1 counter on it, the result looks like this:

Voila! This is a great way to untap the Kraj to distribute more counters. You can make your commander enormously huge, or spread counters around to gain more and more abilities.

I should quickly mention that there’s an exception to this “use my own name” rule. The best example is Mirror-Mad Phantasm, which shuffles itself into its owner’s library, then mills until you find a card named Mirror-Mad Phantasm. If Experiment Kraj gains this ability, it will shuffle itself into your library, but it will still mill until you find a card named Mirror-Mad Phantasm. Since the Phantasm’s ability refers to a specific card name, that stays the same, so you’d end up milling your entire library… but more on that later.

Confused? I hope not, because we’re about to launch into some Kraj-tastic combos.

The Blob

Let’s start by taking a peek at Kraj’s Average Decklist according to EDHREC.

Average Kraj Deck

There’s some excellent stuff happening here. Willbreaker is a great inclusion. It doesn’t have any activated abilities, but it does give Kraj “{T}: Gain control of target creature.” Thousand-Year Elixir is also brilliant, giving your Kraj the chance to start activating abilities the second it hits the field.

The real standouts, however, are the untap creatures.

As with Simic Ragworm, critters like Pili-Pala and Guilder Bairn give Kraj the ability to untap itself. When combined with a mana-producing ability, like that of Argothian Elder or Gyre Sage, you can tap Kraj for mana, use that mana to pay for Kraj’s untap ability, then tap Kraj for mana again, then use that mana to untap Kraj again, and repeat ad infinitum.

Obviously, this opens the door to a ton of possible combos. If Kraj taps for more mana than the cost of the untap ability (such as by combining Argothian Elder and Morphling) then you can repeat this process as many times as you want to get infinite mana. If Kraj gains the untap ability of a Pili-Pala, you can get infinite mana that way, too! If it gains the ability of Knacksaw Clique, you can exile everyone else’s library!

What’s more, you can use several of these synergies to create an army of infinitely large creatures. For example, once you’ve attained infinite mana, you can then use Kraj’s natural tap ability to put +1/+1 counters on your creatures, using your bank of infinite mana to pay for untap costs. Juice up the team to / power and toughness, and swing in for victory! Alternatively, use the abilities of Zameck Guildmage or Arcanis the Omnipotent and draw your entire library! Double-alternatively, put a bajillion counters onto Sage of Hours and take all the turns.

It’s important to note that nearly every single creature in this deck helps enable a Kraj combo in some way. There are a few, like Prime Speaker Zegana and Altered Ego that provide simple, solid value. However, the overwhelming majority of these creatures are cogs for the Kraj machine. Momir Vig, Simic Visionary finds you the creatures you need to assemble your combo. Cytoplast Manipulator lets you take control of your opponents creatures, to ensure they won’t get in your way. Herald of Secret Streams lets you sneak damage through once you’ve given Kraj infinite +1/+1 counters. When playing against a Kraj deck, you’ll have to keep your eyes on every single creature they cast. Horseshoe Crab looks innocent on its own, but Kraj can swoop in out of nowhere and use it to go infinite in a single turn.

Ooze Line is it Anyway?

Okay, so what about the rest of the deck? What are the noncreature spells up to?

Several of these cards fall into the ‘protection’ category. We have the classic Lightning Greaves and Swiftfoot Boots, which protect the Kraj and give it haste, so it can start tapping and untapping immediately. We also have a personal favorite card of mine, Asceticism. We’ve all had those thorny moments where we move to equip Lightning Greaves to our commander, but an opponent casts Path to Exile in response. Asceticism negates any and all chances for your opponents to mess with your creatures. In a deck where your creatures are extra-valuable combo pieces, it’s very important to keep them protected.

We also have a handful of counterspells, which isn’t particularly unusual. Plasm Capture, Voidslime, and Counterspell are standard inclusions for most Simic commanders, as we can see on the Simic Staples page. I do think counterspells are more valuable here than in some other Simic decks, and I’d personally advocate that Kraj play more of them. When your deck can combo off as powerfully as Kraj can, your opponents will have their targets locked on you, which means you need to protect your belongings at all costs.

Frankly, that philosophy applies to the entire Kraj deck. This commander goes infinite, which means there’s no time to dilly-dally. Kraj doesn’t usually take its time; it goes from zero to sixty in the blink of an eye. In fact, Kraj does it with such ease that it’s hard to build a Kraj deck that doesn’t combo off.

I would personally advocate that if you play Kraj, you don’t beat around the bush. Your opponents will know that Kraj can combo off like crazy, so they’ll have their targets locked on you. Lean into that combo strategy a bit more, because that’s what Kraj does best. To that end, cards like Inexorable Tide, Vorel of the Hull Clade, and Contagion Engine kind of get in the way. They’re excellent cards, to be clear, but Kraj doesn’t need them, because it’s too busy going infinite.

I’ll have some more recommendations for Kraj in a bit, but for now, we need to turn our attention to our other activated ability collector: Mairsil, the Pretender.

Let’s Pretend

Mairsil, the Pretender is bizarre, wonky, and just as difficult to build as he is to contain. Like Kraj, Mairsil has an extraordinary history, beginning with his capture of Ith, High Arcanist, and ending with a ring that led to the ignition of Jaya Ballard, Task Mage’s planeswalker spark. Like Kraj, he absorbs the abilities of other creatures. However, unlike Kraj, he can also take them from artifacts. Every time he hits the battlefield, he’ll put an artifact or creature card from your hand or graveyard into a cage, where he’s able to steal its activated abilities. This gives him a much larger array of possible combos than Kraj—except that he can only activate each ability once per turn. You can’t just slap together a Staff of Domination and a Gilded Lotus to go infinite; Mairsil has to put in a lot of work if he wants to go crazy.

Let me start right away by discussing one of the most important (and headache-inducing) cards for Mairsil: Quicksilver Elemental. A lot of folks postulated that using the Elemental to copy Mairsil’s abilities would get around the “once per turn” clause. However, Eli Shiffrin, the Rules Manager has clarified here that Mairsil’s restrictions will carry over when copied. Additionally, the Gatherer Ruling on Quicksilver Elemental also mentions abilities with restrictions:

That said, Quicksilver is still very useful. Despite the restriction, you can use Quicksilver Elemental’s ability multiple times, and each time you do, it’ll get another batch of activated abilities. Each individual ability can still only be used once per turn, but you can keep gaining more individual abilities. If you activate this ability enough, the result could look something like this:

In this example, if Quicksilver Elemental steals abilities from Mairsil, you can then tap Quicksilver Elemental for mana per the stolen Gilded Lotus ability, then untap it with the stolen Horseshoe Crab ability. Those abilities are now spent; you can’t activate them again this turn. However, you can reactivate Quicksilver Elemental to steal Mairsil’s abilities again, getting a new set of those abilities. Once again, if you repeat it enough, you’ll get infinite mana.

Additionally, Deadeye Navigator, often known for doing broken things, can get around the “once per turn” restriction as well. Mairsil can’t cage Deadeye Navigator for any benefit, since the Navigator doesn’t have a natural activated ability. However, if it’s on the battlefield and Soulbonds with Mairsil, it can flicker Mairsil, immediately returning him to the battlefield. Mairsil will now treated as a new game object, which means he can use his abilities again. If you have Anger in the graveyard and Gilded Lotus in a cage, you can therefore tap Mairsil for three mana, pay two to flicker him, then immediately tap him for three more mana, flicker him again, and so on.

Alright, we’ve established a few ways to bend the “once per turn” restrictions, but there are some other combos we should examine as well. To do that, let’s take a peek in Mairsil’s dungeon to see what else he’s got in his cages.

A Rat in a Cage

Here’s another Average Decklist, this time for Mairsil. Check it over carefully, and see if any synergies jump out at you.

This is a pretty big puzzle to piece together, so let me point out a few of my favorite combinations:

Anthroplasm + Sage of Hours: Mairsil can only use his abilities once per turn… but if you’re taking extra turns, that restriction doesn’t matter, does it? By paying five mana, Mairsil can put five +1/+1 counters on himself with Anthroplasm’s ability. Then, using Sage of Hours, you can take an extra turn. On your next turn, repeat this process. On the turn after that, repeat it again. On the turn after that… well, you get the idea.

Tree of Perdition + Hateflayer: You don’t need to activate these abilities multiple times for it to be effective. Using Tree of Perdition’s ability, Mairsil will exchange his four toughness with an opponent’s life total. Then, using Hateflayer’s untap ability, Mairsil can untap himself to deal damage equal to his power to that player. It’s an automatic kill, and it’s super effective. (This also works by replacing Hateflayer with Spikeshot Elder).

Aetherling + Nevinnyral’s Disk: Nev’s Disk has a lot of uses, especially in Planeswalker decks, since it destroys all nonland permanents except planeswalkers. However, Mairsil uses Disk in ways even Planeswalkers can barely fathom. Take careful note of the Disk’s wording: it doesn’t sacrifice itself as part of the activation cost. Thus, if Mairsil activates his Disk ability, you can hold priority, and then activate the Aetherling ability. This will blink Mairsil off the battlefield, then destroy all nonland, nonplaneswalker permanents. After the carnage, Mairsil returns safely at the beginning of the next end step, and can cage another card along the way. You can continually keep the board clear of all pesky permanents until you’re ready to win the game. Alternatively, you can use Soul of New Phyrexia’s ability to make all of your permanents indestructible, leaving only your board intact but demolishing everyone else’s!

(Oh, and I’d be remiss if I failed to mention Mirror-Mad Phantasm again. Remember, by activating this ability with your commander, you’ll mill your entire library. From there, you can Dread Return a Laboratory Maniac for a zero-library victory. According to EDHREC, only 19% of Mairsil players are using the Phantasm in their decks, so this doesn’t seem to be a typical strategy for Mairsil, but it’s worth knowing.)

Proper Planning

Mairsil has a “once per turn” restriction, and several of the combos mentioned above manage to skirt around that limitation. Instead of avoiding it, though, we can embrace it. Mairsil only lets you activate abilities once each turn, but not just once on your turn. If you throw a tap ability and an untap ability into a cage together, such as Shauku, Endbringer and Morphling, Mairsil can tap and untap himself on your turn, then on Opponent 1’s turn, then again on Opponent 2’s turn, and so on. You don’t need to go infinite to get insane value off of Mairsil’s synergies.

Finally, direct your attention to the cards Mairsil can’t cage. Search for Azcanta, Buried Alive, Fact or Fiction, Faithless Looting, Windfall, and several more. These cards are Mairsil’s lifeblood. Mairsil needs to find his precious underlings before he can cage them. He’d rather not cage a card from his hand; if he enters the battlefield and exiles a card from your hand, but immediately falls to a Terminate, you’ll have paid a whole lot of mana to discard a card. That doesn’t feel good.

Instead, Mairsil uses his spells to put his precious treasures in the graveyard, while drawing other useful cards along the way. Use Faithless Looting and friends to discard your Morphlings, where Mairsil can exile them later. Looting effects help supply your commander with targets while keeping you up on card advantage.

Lastly, I have to quickly highlight a card I’ve already mentioned in a prior combo: Aetherling. This is the #1 card for Mairsil, showing up in 89% of Mairsil decks on EDHREC. That’s a higher percentage than Sol Ring, which is at 86%.

This is easily Mairsil’s best friend, and the first card I’d want to put into a cage. First of all, blinking is a fantastic way of triggering Mairsil’s cage ability. We can’t keep casting Mairsil from the command zone every time we want to exile a new card. This is why we see Pack Rat and Cavern Harpy in the Average Decklist, since they allow you to trigger Mairsil’s enter-the-battlefield ability without bothering with Commander Tax.

With Aetherling’s blink ability, Mairsil becomes nearly immune to removal, dodging Chaos Warps and Wrath of Gods alike. This is useful because, frankly, it’s hard to cast Mairsil multiple times. He’s in Grixis, which means there isn’t a lot of access to mana ramp effects. The best options are mana rocks, and Mairsil keeps putting those darn things into cages! This makes blink effects doubly important for Mairsil; not only does he dodge removal, but he can repeatedly enter the battlefield and cage more and more cards.

I think Aetherling in particular distinguishes Mairsil’s strategy from Kraj’s. Kraj goes infinite almost as if by accident, and can potentially even do so the first turn it hits the battlefield. Those combos are powerful, but if Kraj has a weakness, it’s predictability; Kraj assembles a tap-untap duo and goes to town, without much variation. Mairsil, on the other hand, is decidedly gradual. He can’t go full throttle right out of the gate, because he needs to put things in cages first. He is forced to take his time, which makes him both methodical and unpredictable. While Kraj goes infinite in roughly the same fashion ever game, Mairsil might never assemble the same synergy twice in a row. With his Aetherling effects he can stay aloof, watching the game from afar, hoarding an ultimate toolbox of trinkets to assist him depending on the state of the battlefield so far. What Mairsil lacks in speed, he makes up in control, keeping himself safe and keeping his opponents in suspense.

Cards to Consider

I’ve got some suggestions below for cards that I think could stand to see more play in both of these decks. Take a look:


Glen Elendra Archmage Walking Ballista

  • Glen Elendra Archmage: This one is spendy, and I always advocate playing within your budget. If you have an Archmage, though, this is a fantastic place for it. Counter any harmful spell that comes your way, then tap Kraj to put a +1/+1 counter on the Archmage. This will cancel out the -1/-1 counter, which leaves you with a fresh Archmage once again.
  • Spike Weaver: This might be my favorite Fog in the game, purely because it’s repeatable. In Kraj, you can keep this bizarre little caterpillar well-stocked with +1/+1 counters, so you’ll never take damage unless you want to.
  • Stubborn Denial: Like I mentioned above, I think Kraj could stand to run more protective spells. Stubborn Denial is a one-mana Negate. Swan Song can keep your board free from prying eyes. Heroic Intervention can stop all manner of problematic spells people will point your way. If your deck has a combo, you need to keep it safe, and Simic has lots of fantastic ways to do so.
  • Walking Ballista: In decks that can get infinite mana, this creature is a colorless Fireball.
  • Selvala, Heart of the Wilds: This lady makes absurd amounts of mana, and Kraj is very happy to gain access to her ability. Again, though, it’s spendy. Viridian Joiner is a possible replacement, since Kraj can use its ability to tap for upwards of four mana.


Argent Sphinx Prismatic Geoscope

  • Glen Elendra Archmage: That’s right, I’m recommending this card for both commanders. This protects Mairsil, gives him another enter-the-battlefield trigger, and is obnoxiously powerful even if you don’t put it in a cage. Pair it with Aetherling to blink your commander and remove the -1/-1 counter, so you can counter even more spells!
  • Argent SphinxThis isn’t as consistent as Aetherling, but it is another potential blink outlet. Mairsil should have an ample number of artifacts to enable Metalcraft, so this seems like a safe backup.
  • Crystal Shard: This handy little artifact is occasionally used by Maelstrom Wanderer players to re-cast their commander. It’s helpful for Mairsil in the same way, bouncing him to your hand when danger approaches, so you don’t have to pay commander tax. Aside from that, it’s a nice “Are You Watching Closely?” tax on your opponents, rendering them unable to tap out lest you bounce their best creature back to their hand.
  • Prismatic GeoscopeThis is no Gilded Lotus, but once it’s in a cage, who cares? As long as you get your three basic land types, this will be a nice addition to Mairsil’s collection of exiled mana rocks.
  • Galecaster Colossus: This Giant Wizard puts in a disturbing amount of work in Inalla, Archmage Ritualist decks, and I think it has nice potential here too. Mairsil will probably be your only Wizard, but once he has the Galecaster Colossus ability, he’s in business. Remember, this ability doesn’t contain a tap symbol, so you don’t need haste to activate it. Mairsil can tap to bounce the most threatening permanent on the battlefield, blink away with Aetherling, and immediately tap again when he returns. He can also tap himself to do an impression of Cavern Harpy, saving himself from harm. There’s a lot of nasty potential with this card, and I think Mairsil would make great use of its flexibility.


That’s it for this week’s Activated Ability Showdown. Which of these commanders most intrigues you? Are you a fan of the classic Kraj, or would you rather play pretend with Mairsil? Let me know below. Oh, and don’t forget to vote for the Showdown you’d like to see next!

Til next time!



Joseph Schultz is a Creative Writer from Seattle who works in a library by day and shuffles libraries by night. He has played Magic since 2005 and EDH in particular since 2010. He was also born exactly one year before Magic the Gathering, which he thinks is probably some kind of sign.