Commander Redo: Mairsil, The Pretender Done Right

Deckbuilding is probably the thing I love to do most in all of Magic and building for Commander is the best of the best. But sometimes you cook up a deck that you think is going to be awesome… and it turns out to be disappointing.

Case in point: the deck I originally built for Mairsil, the Pretender when it first came out in Commander 2017. I wrote about it here, but when I was pulling the cards together to build the list in paper, I went outside the lines and added a bunch of other cards that I knew would be awesome in the deck. Once I got the new list finalized, I eagerly pulled it out at my local game shop and… proceeded to shut everyone else down once I got a couple of key cards caged with Mairsil. It took me a while to win but everyone else just stopped being able to cast anything relevant. I could either counter it, or destroy it, and meanwhile Mairsil was nearly impossible to stop. It really wasn’t very fun for anyone, not even me.

The next game I played Mairsil I was properly treated as the Archenemy and everyone ganged up on me to stop my shenanigans. I didn’t have much fun in that game.

The last game I played with Mairsil I had an awkward draw where I didn’t really draw any of the really good cards to cage with Mairsil, and the deck just seemed clunky and awkward. Meanwhile, everyone was gunning for me.

So, I took the deck apart.

Here was the sort of cards that are really, really powerful in Mairsil but didn’t seem to lead to very interesting gameplay in practice:

The thing is, Mairsil is just such a weird and interesting card to build a deck around, I knew I wanted to come back to it, with the goal of cooking up a decklist that would not be so oppressive and miserable to play against. As we await the preview seasons for Ikoria: Lair of Behemoths and Commander 2020, the day has come for a Commander Redo for Mairsil, the Pretender!

Let’s refresh ourselves with the game notes on Mairsil, and there are quite a few of them:

The exiled cards remain exiled with cage counters when Mairsil leaves the battlefield. If Mairsil returns to the battlefield, it will see all of those exiled cards with cage counters on them.

If another player gains control of Mairsil, it will have the abilities of only cards that player owns in exile with cage counters on them.

Activated abilities contain a colon. They’re generally written “[Cost]: [Effect].” Some keyword abilities (such as equip) are activated abilities and will have colons in their reminder text. Mairsil won’t gain triggered abilities (which start with “when,” “whenever,” or “at”).

If an activated ability of a card in exile with a cage counter on it references the card it’s printed on by name, treat Mairsil’s instance of that ability as though it referenced Mairsil by name instead. For instance, if Mairsil exiles Magus of the Mind, the cost to activate the ability includes sacrificing Mairsil, not sacrificing Magus of the Mind.

If one of Mairsil’s abilities is countered, most likely because its target became illegal before it resolved, it can’t be activated again in the same turn.

If multiple cards exiled with cage counters on them have the same ability, Mairsil will have multiple instances of that ability. Each may be activated once each turn.

If you have a creature enter the battlefield as a copy of Mairsil, its first ability triggers. You won’t be able to activate any abilities before the “legend rule” applies, but the triggered ability will still let you exile another card with a cage counter regardless of which Mairsil you keep.

If Mairsil gains an activated ability that’s normally linked to a non-activated ability of the card it came from, the ability Mairsil has isn’t linked to any ability. For example, if Mairsil exiles Prototype Portal, the activated ability creates no tokens at all; it doesn’t create Prototype Portal tokens.

If Mairsil gains an activated ability that’s normally linked to another activated ability of the card it came from, those two abilities Mairsil gains are linked for as long as Mairsil remains on the battlefield. For example, if Mairsil exiles Izzet Chemister, cards exiled with the first ability Mairsil gained from Izzet Chemister can be cast if you activate the second ability it gained that way. Izzet Chemister itself can’t be cast this way, and if Mairsil leaves the battlefield before activating that second ability, the cards exiled with that first ability are lost forever.

If Mairsil has a crew ability, creatures can crew Mairsil. It’ll become an artifact creature, but its power and toughness remain unchanged.

If Mairsil has an equip ability, activating it won’t cause anything to happen. Mairsil doesn’t become attached to a creature. They may remain friends.

So, what sort of cards should we be looking for when building a deck around Mairsil? First of all, we’ll want lots of creatures and artifacts with cool abilities to cage, especially those that have multiple abilities. We’ll also want ways to have Mairsil leave and enter the battlefield more often than just dying and being recast from the command zone so we can accumulate a nice spread of caged cards. And we’ll also want ways to copy Mairsil or Mairsil’s abilities so that we’ll have multiple creatures that can take advantage of the caged cards.

Okay, let’s get cooking!

1. Thassa, Deep-Dwelling

Theros Beyond Death offers our deck an indestructible way to exile Mairsil and bring it back to the battlefield, which will give you the opportunity to cage another card. I doubt that we’ll ever have enough blue devotion to turn Thassa into an actual creature, but Thassa’s activated ability can come in handy here and there.

I’m including quite a few other ways to “blink” Mairsil for extra cage cards:

Tome of Legends takes advantage of all the blinking, since each time Mairsil enters the battlefield you get a new page counter on the Tome. This should provide a cheap, steady supply of card draw.

2. Identity Thief

Why should Mairsil have all the fun with the caged cards? Identity Thief does great work here since it’s another way to blink Mairsil, and while Mairsil is in exile, the Identity Thief version of Mairsil can use any abilities on caged cards it could use while tapped and attacking.

I’ve got some other ways to take advantage of Mairsil’s caged cards:

Sakashima the Impostor and Spark Double get to stay out on the battlefield doing Mairsil stuff alongside Mairsil. And if we can equip Mairsil with Helm of the Host we can make a nonlegendary copy of Mairsil that also gets to cage a creature or artifact.

If we’ve caged Pack Rat with Mairsil, whenever anyone tries to kill Mairsil with targeted removal and we have enough mana open, we can discard a card to make a copy of Mairsil and let the targeted Mairsil die to the legend rule. You even get a cage trigger and possibly have just discarded something sweet you can cage.

3. Tree of Perdition

Speaking of cage triggers, how about caging Tree of Perdition? If someone is getting too silly with lifegain you can switch Mairsil’s toughness of four with their life total, which is conveniently also Mairsil’s power. And with all the blink effects we have, you can reset Mairsil’s toughness back to four and do it again to someone else.

There are quite a few creatures with cool abilities we’d like to cage:

I’m going to have one of each of the Morphling variants that we can have in Grixis, but instead of Morphling I’m going to run Aetherling since it’s another way to exile Mairsil and bring it back to the battlefield. Endling’s undying ability is also nice, bringing back a Mairsil that dies with a +1/+1 counter.

Quicksilver Elemental’s a hoot since it’s a way you can copy abilities from opponent’s creatures too!

4. Pendant of Prosperity

Pendant of Prosperity is a card I’ve been wanting to be good for a while now, but in this deck it’s a powerhouse. Cage it and Mairsil taps for two mana. You get to draw a card, play a land, and then draw a card and play a land. Now that is some serious value!

The Cauldron of Eternity was made to be caged with Mairsil—you get all that nice reanimation benefit, with none of the huge mana cost to cast or its replacement effect for creatures we control dying.

Aetherflux Reservoir is another interesting artifact to cage, especially if we’ve got a way of giving Mairsil lifelink and we’re above 50 life!

5. Basalt Monolith

Caging Basalt Monolith is awesome since you can tap Mairsil for three mana and without the drawback of not untapping during your untap step. And you can also make use of the untap ability to use other tap abilities again.

Here are a few other artifacts we can cage so that Mairsil can tap for colored mana:

6. Training Grounds

Since we’re all about activated abilities, Training Grounds is a slam dunk to reduce the cost by up to two colorless mana. I’m including some other ways to boost Mairsil:

Shadowspear or Basilisk can give Mairsil the lifelink ability we need to go nuts with the Aetherflux Reservoir ability!

7. Anger

Many of the abilities on cards I’m caging with Mairsil require tapping to activate, so being able to use them right away will be very handy. Anger in the graveyard with a Mountain on the battlefield is a nice clean way of assuring Mairsil – and all of my creatures – have haste.

Here are a few other options:

8. Spellskite

We’re going to want to have some ways to interact with our opponent’s plans, especially removal spells that target Mairsil—Spellskite to the rescue! Here are some other cards that will come in handy for a variety of situations:

9. Arcane Signet

Many of our abilities cost mana, so I expect that our deck will need a bunch of mana to do everything we need it to do. I’m including as many of the usual suspects as I can find slots for, but the best of the bunch is certainly Arcane Signet. Two-mana artifacts that tap for mana help us cast Mairsil on Turn 3, which is exactly where we want to be.

10. Damnation

Last but not least, I’m adding cards that will destroy things that need destroying, and the best of the bunch is Damnation. Even if Mairsil gets destroyed alongside everyone else’s creatures, that just means you get to cast Mairsil again and get another cage trigger.