Other People’s Decks: Dan Sheehan’s Rin And Seri Changelings

It’s raining Cats and Dogs…and Things? Sheldon Menery shares a Commander MTG deck by Dan Sheehan that mixes a classic horror film with changelings.

Rin and Seri, Inseparable, illustrated by Leesha Hannigan

Sometimes you come across a deck so sweet you just have to share it.  Friend of the format, Commander Sphere co-host, and comedy writer Dan Sheehan has such a build.  He’s taken Rin and Seri, Inseparable and built a Changeling deck with it.  He played it recently on the Commander Rules Committee (RC) stream and it was beautiful.  He got stymied by a few well-timed battlefield sweepers or he would have otherwise been golden. 

What struck me was that he was playing Shapeshifters in colors other than blue.  Naya isn’t really famous for its changelings, but he really got there.  Because most of the creatures he casts are both a Cat and a Dog, they trigger the commander twice, building a saucy battlefield state pretty quickly.  I asked Dan what inspired him to build the deck, which has a special additional theme.

In Dan’s Own Words

I’d been trying to build a changeling deck for a long time. Shapeshifters enable nearly any strategy you can think of and for that reason, changeling decks typically wind up being five colors. Now, I love a good five-color deck.  I’ve been trying to make Atogatog work for about as long as I’ve been playing Commander—but that’s another story for another day. As perfect as a deck with access to every color and every tribe sounds from a mechanical standpoint, it always lacked flavor. With access to all five colors and having tried everyone from Morophon, the Boundless to The Ur-Dragon at the helm, the deck had a hard time establishing its own identity.

I’m a story-first Commander player. When I build a deck, What I care most about is that it feels personal and evocative. I didn’t just want a deck that could take advantage of every tribal synergy, I wanted a deck that embodied the unsettling, ominous, atmosphere of the original changeling cards. Take one long look at Crib Swap: it’s horrifying! I wanted something that captured that horror, like the Magic equivalent of John Carpenter’s The Thing and then it hit me: why not make the Magic equivalent of John Carpenter’s The Thing?

In The Thing, a murderous shapeshifting horror terrorizes an Antarctic research base by taking the form of its own residents, starting innocuously with a dog. The movie beautifully takes advantage of our cultural love for man’s best friend and the deck would need to as well, so I picked Rin and Seri, Inseparable as my commander. With each Changeling spell cast, Rin and Seri would get me both a Dog and a Cat token. More Changelings mean dealing more damage and gaining more life, especially when cards like Maskwood Nexus get involved to put my tokens to work.

I wanted my win condition to match the two forces at play in the movie: a rapidly multiplying eldritch nightmare and a pilot armed with the only thing that can kill the beast: a flamethrower. Using cards like Cryptolith Rite and Cryptic Gateway, the deck’s few Eldrazi can be summoned for a monstrous finisher. If you’re lucky enough to assemble the combo of Changeling Berserker, Changeling Hero, and Changeling Titan with something like Impact Tremors or Terror of the Peaks on the battlefield, you can generate infinite enters-the-battlefield effects and burn the whole table to the ground.

There are certainly more efficient Changeling decks out there but this is the most fun iteration of mine that I’ve ever played. By putting in the extra time to make it my own and adding the challenge of doing so in Naya as opposed to WUBRG, I built something unique that’s a blast to pilot.

Dan’s List

My Take

Dan definitely searched through quite a few cards in order to find enough Shapeshifters.  My three favorites are Changeling Titan, Changeling Berserker, and Changeling Hero.  I’m a big fan of the champion a creature ability, which lets you hide away a creature until the champion goes away.  I like to use the ability to get extra enters-the-battlefield triggers off creatures or protect something valuable if I know a battlefield sweeper is coming.  Here, Dan can also just eat one of the many tokens the deck that the deck creates. He can even put the triggered ability of the Changeling Titan, Changeling Berserker, or Changeling Hero on the stack first and then Rin and Seri’s so that he can eat the one with summoning sickness. 

The combo that Dan mentions with all three champion creatures involves have one of them on the battlefield and then sacrificing it to the enters-the-battlefield triggered ability of a second.  Then you cast a third (or have it enter the battlefield some other way).  It champions the one that’s on the battlefield, bringing back the original from exile.  It creates a triggered ability that exiles the third one, which then comes back in and starts the cycle all over again.  If you have something like Impact Tremors or Terror of the Peaks in this deck and the cycle is uninterrupted, you’ll get as many of them as you need to kill everyone.  Unfortunately, Rin and Seri only triggers on casting Cat or Dog spells, so it’s not much help here. 


While Dan took some conventional tribal lines with creatures and cards you’d expect (like Beast Whisperer in a creature-heavy deck), he also made some saucy choices.  Let’s take a look at some of my favorites.

Manaweft Sliver

It hadn’t occurred to me that everything is also a Sliver.  It was one of those “of course!” moments that got me thinking about what other creature types we might do something with.  There was an immediate answer.

Wirewood Savage

Along with nearly everything in the deck being a Sliver, it’s also a Beast.  Nicking the card draw off Wirewood savage is very clever indeed.  With the appropriate colors being in the deck, I wonder if Contested Cliffs works too.

Akroma's Will

I feel like I still don’t see enough of this card.  It’s recent enough that I can’t call it a Hidden Gem—more like an ignored one.  I’m drawn to it for the defensive use of making everything indestructible, as he uses Cosmic Intervention and Rootborn Defenses.  The offensive use of flying, vigilance, and double strike to go along with protection from all colors and lifelink means that there are some alpha strike capabilities in the deck. 

Impact Tremors

This little common from way back in Dragons of Tarkir should get a little more love.  Sure, it’s not Goblin Bombardment, but what is?  While it doesn’t seem like much, those little bits of damage pile up.  When you’re creating lots of token creatures, the pile gets higher.  What’s compelling about Impact Tremors is that no one is going to destroy it unless they’re directly facing lethal damage from it in the near future.  There are always bigger and juicier targets in Commander, letting our little earthquake slide on by. 

Alms Collector

It goes along with the Cat part of the tribal theme, but this is just a card that is criminally underplayed. It has a decent body and stops insane draw strategies from getting out of hand.  This kind of power gating is what white is become good at and I’m here for it.  I’d call this a reasonable protection card.  Alms Collector sits in design space that’s worth exploring.  It doesn’t completely stop someone from doing something; it just puts limits on it while giving you a benefit at the same time.  Of course, when someone tries to cast a Wheel effect, I’m all for the blowout.

Kozilek, Butcher of Truth

I’ve seen plenty of people try to justify Eldrazi for flavor reasons and they’re just rationalizing playing big, dumb cards (really, it’s okay to just play big, dumb cards for no other reason).  Dan has won the flavor battle with Kozilek and Ulamog, the Ceaseless Hunger.  Flying spaghetti monsters (from outer space) definitely qualify as something in The Thing. 

Eldrazi Conscription

And now we come to the chef’s kiss of the deck, the Colossification of the ancient days.  Way back when Mythic Bant was a deck that we’d play, we didn’t pay eight to cast it.  I suppose that this deck can generate the mana, especially with Cryptolith Rite hanging around.  Even the smallest Cat becomes a force to be reckoned with under Eldrazi Conscription.

Cards Worth Considering

Dan’s Moxfield list also notes a few cards that he’s thinking about.  Ajani’s Presence is good for saving Rin and Seri from a battlefield sweeper for just one mana and being able to keep other things if you have the mana.  The thing is that, if you have the mana, then options like Faith’s Reward or redundancies for Rootborn Defenses such as Make a Stand and Unbreakable Formation, which he mentions, become viable.  The other card he lists falls into that space as well, the always-lovely Flawless Maneuver.  The if you control a commander design space can be a little scary, but Flawless Maneuver seems fine.  It’s defensive as opposed to the aggressive Jeska’s Will

Chameleon Colossus

One Shapeshifter that Dan doesn’t have on his list is Chameleon Colossus.  For me, this is one of the best of them for its offensive upsides.  Doubling its power and toughness just once can make it pretty big; twice can be lethal.  Don’t sleep on protection from black, either.  It gets around the color with the best targeted removal, so all you need to worry about are cards like Swords to Plowshares and Path to Exile

There are two artifacts I’d consider here was well:  Eldrazi Monument and Coat of Arms.  Eldrazi Monument can use the many tokens the deck creates to stay around, thus making all the Cats and Dogs flying.  Coat of Arms will make them all stupidly large. The downside of Coat of Arms, and the reason we don’t see it much, is that it’s symmetrical.  It offers the bonus to all other decks as well, so if you’re facing another tribal deck it could get hairy.  I recognize that both cards don’t really fit thematically anywhere into Dan’s The Thing build, so I get not wanting to pick them. 

I’m a huge fan of the fact that Dan used elements of the book and the three major film productions of The Thing to make a theme deck.  Commander is the only format in which you can manage something like this.  Focusing on fun and creativity first and winning second (and this deck can definitely win), he’s hit a very sweet spot in Commander.  A year from now, nobody’s going to remember a generic value pile that won more games, but we’ll still be talking about Dan’s deck for some time to come.  This really is the spirit of Commander. 

As always, you’re welcome to pop over to the Commander RC Discord server to discuss this article or any number of other topics with over 5,000 registered users.  Hope to see you there.

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