Toxrill Proliferate: Standard Deck Tech

Crimson Vow will be here before you know it. The Wizards of the Coast design team hit a home run with new and interesting commanders to build around. That may not be the case for cEDH but at casual tables diversity grows. One of the commanders that caught my attention is Toxrill, The Corrosive. Of the cards I was expecting, a giant slug was not one of them. He presents a new twist on Dimir commanders. One that can clear the board and then control it. 

Solving Toxrill

Part of Toxril was solved almost immediately. He synergizes well with Sludge Monster, who made my Five for Five list for Innistrad Midnight Hunt. They both put slime counters on creatures. With those slime counters The Sludge Monster turns all non horror creatures into 2/2 and limits their special abilities. Toxrill gives them -1/-1. With these two creatures out on the battlefield, just two slime counters and creatures will be dying everywhere. All this due to a slime like blob. It also prevents combo mischievousness by eliminating special abilities from creatures. For example, Selvala Heart of the Wilds and Sword of the Paruns. The list goes on and on. 

Toxrill triggers on each end step. Wizards got this right. In a standard four player pod the two players to your left should have no creatures in play. The player to your right should have only 1/1 creatures in play. Then if you attack with Sludge Monster, you will remove one creature from the player to the right. Any remaining creatures die on your end step. However, while this is an excellent synergistic combination of cards, we can not count on this combination and being able to protect it every game. Creatures are the easiest form of permanent to remove. Instead, we MUST build towards this synergy but not count on it because it WILL be removed. There will be times where Toxrill will have to do all the work. It’ll take five or six end steps to remove an offending creature.  

The Solution    

Most have already figured out the solution. If you can proliferate upon placement of the slime counters before your turn, then you can kill remaining creatures on the battlefield. This opens the path of attack of the player that is most dangerous to us. They’re in heated competition with us to win the game.

Our options are limited if we want to attack the biggest threat. Contagion Clasp and Contagion Engine can proliferate easily once the slime counter is placed.  The downside is some cards like Inexorable Tide and Flux Channeler require conditions we must achieve in order to proliferate. The condition is is casting spells, and the deck as constructed only contains six instants and nine sorceries. Others like Thrummingbird can not trigger at all. We can settle to attack just anyone. It’s better to have freedom of choice in attacks. Because of this there are specific proliferate cards this deck wants in play. 


Ten cards are allocated to card draw plus additional cards that have other uses with incidental card draw on them. On top of that, the deck also contains five tutors to round out the Card Draw – Card Quality package. These cards allow us to dig deep into our deck. Then we can find the proliferate cards we need to accomplish a board wipe and attack whomever we desire. If we can’t find one by digging with Drawn from Dreams, Fact or Fiction, and other card draws, we will tutor for it.

The deck would prefer to tutor for the Sludge Monster or  the means to protect Toxrill, but we can still manage boards as long as we have proliferate abilities. If you must tutor for a proliferate card, then Karn’s Bastion is recommended. The land, Karn’s Bastion, is less likely to be removed. Proliferate is integral to the deck, and there are a lot of cards that synergize with it. Thus, proliferate is a value engine to itself. 

The Key Three or Synergizing Proliferate

You can find the decklist below, or if you would like a visual representation, check out the deck on Archidekt

Proliferate is a challenge in Dimir Decks. The first thing people think of is proliferating +1/+1 counters. Black has cards that place counters where blue has few. Also, there is not a cohesive strategy with these counters. Cobbling together Vampires is possible. If we want Vampire counters, then the deck would be better served to play Edgar Markov as commander instead. 

Rather than force a +1/+1 counters theme, we will put together a counters package that is a value engine. The deck uses all the tools available in Dimir colors. The deck has gotten creative with counters to make it work. Here are three ways to capitalize on the proliferate mechanic. 

Level Up 

First, there is the level up mechanic. If we get just one counter on a level up creature, then we can level it up with proliferate. Sometimes it costs less mana to level up a creature then it is to proliferate. Depending what other counters we have on the battlefield determines whether we want to proliferate or just level a creature up. For example, Lighthouse Chronologist requires just one blue mana to level up. If our opponents have three or more creatures on the battlefield with slime counters on them, then it is better to proliferate. This removes the threats that opponents have. When we are carfeful with how we spend our mana, we can accomplish both objectives. Echo Mage, Enclave Cryptologist, and Hada Spy Patrol round out this category of cards.

Beware Class Cards

Similar to the level up mechanic are class cards. It would seem that since you level them up that you would put counters on them. Unfortunately, this is not the case. No counters are placed on the cards. The level is just the status of the card when you level it up. You can’t bypass levels with these cards. Despite this, Wizard Class is solid for this deck. It provides no maximum hand size and card draw. Both are advantageous for the deck. Level three adds +1/+1 counters to your creatures whenever you draw a card. While the deck is not focused on winning via combat, more powerful defenders and more incidental damage could put you in the position to take out a player or two via combat. Warlock Class does not help with the proliferation triggers. But it’s additional card draw and a win condition when it reaches level three.  


Atraxa players know that superfriends is an effective way to build proliferate decks. While the deck is not a dedicated superfriends deck, planeswalkers are a solid include for the deck. Once Toxrill gets rolling, the ability for our opponents to remove our planeswalkers are reduced. This allows a plethora of abilities for our side of the battlefield. We won’t cover them all here, but some of the highlights are as follows.

Liliana, Dreadhord General does it all creating tokens for defense, removing creatures, and drawing cards. It also wins games with her ultimate ability. Narset, Parter of Veils shuts down card draw. Proliferate provides a way to raise her loyalty and keep that ability safe. Jace, Unraveler of Secrets brings incidental card draw and temporary removal while providing additional card advantage with his ultimate ability. Opponents will need to burn a spell in order to play a spell. It also shuts down most counterspells on your opponent’s turns. Tamiyo, the Moon Sage protects herself and provides card advantage too.


Poison, while strong, is a mechanic that limits your ability to win.

Commander Clinic

Proliferate also works with poison counters. Poison is a very sensitive issue in commander. It effectively reduces a player’s life total to ten. With proliferate on the battlefield, players often are quite scared of poison. Your opponents will have a tendency to turn your deck into the archenemy deck. Commander Clinic recommends a very conservative approach to poison. Part of winning games is being in a position to win games. Poison, while strong, is a mechanic that limits your ability to win. In this deck’s case, if you can keep your opponent’s board clear with Toxrill, then there’s a chance you may survive to win. You must be very careful deploying your poison cards. 

For this reason only two poison cards were included in the deck. The first is Viral Drake. It has a built in proliferate ability that is usable again and again. The deck can generate significant amounts of black mana to fuel the colorless activation of the 3U casting cost. More importantly, from a politics standpoint, a case can be made that I don’t want to attack. I only want to proliferate and protect myself from attackers.  

Skithiryx, The Blight Dragon is a different story. It’s a 4/4, has evasion and a built in haste ability. It is meant to attack and take down opponents. It works best as a defense only argument when you do not have the sludge monster in play. If you can convince your pod this is the case, then you deserve The Golden Tongue Award. In reality, you only want to play him when you have the battlefield well in hand. Then, when archenemy politics happen, you can withstand the attack. 

Additional Politics

Recently, The Command Zone did a countering politics episode. It covers how you should respond when deals are offered. One important tidbit emphasized is the archenemy situation. The Command Zone makes an excellent point that sometimes it is better for the player in last place to not become part of the archenemy scenario. It’s better to let the players in the second and third place position to use their cards. Then, the fourth place player conserves cards and uses that time to catch up. 

With playing Skythrix you may find the table turning to an archenemy scenario. When you do, it’s quite important to leverage this concept to the fourth place player and point out that by joining such an archenemy situation, it would be wise for you to take them out. Doing so creates a two on one scenario instead of a three on one. Point out that if they use their cards against you, they will be less likely to defend against such an onslaught. Instead, you can focus your resources elsewhere. During this time, they can capitalize on building their board to win the game. It’s beneficial to them no matter how the archenemy scenario resolves.

When this tactic’s successful, you have effectively created a two on one scenario for a couple of turns without using a single card. That is excellent because your goal should be to remove your biggest threat. If you can reasonably do this, then your odds of winning the game improve significantly. Much like Dr. Strange giving Thanos the Time Stone, you are in the end game now. 

Pet (cards) Synergies 

Commander decks are not built with all staples. There are cards that are less powerful that synergize well with your deck that become stronger than the sum of its parts. Proliferate is one of these strategies that ask for some specific cards that are sometimes outside the norm. Here are some additional strategies that were included in the deck that help our proliferate theme. 

Extra Turns

Teferi, Master of Time is arguably our most powerful planeswalker. He is a must remove card. Teferi activates on everyone’s turn. He draws cards incidentally while phasing out threats that would attack him. Most importantly, his ultimate ability brings us two additional turns. From there we should be able to put our deck in a position to win the game. With Teferi in the deck and the excess amount of card draw (26 total cards), it is easy to lean into an extra turns theme with few cards dedicated to it. Magistrate’s Scepter removes three counters from it for an extra turn. Lighthouse Chronologist levels up for additional extra turns as well. 

Expropriate would be an excellent fit for the deck as well. So would Nexus of Fate. Unfortunately, room for these cards was not able to be achieved. In its place Unwinding Clock will untap our mana rocks and our contagion artifacts. This creates additional proliferate activations that synergize with what the deck wants to do most. Lux Cannon is another card that untaps with Unwinding Clock. The Cannon can remove any permanent and is one of our answers to pesky enchantments. Unwinding Clock, while doing little on its own, is hands down more synergistic than either extra turn card. 

Warlock Class, a win condition mentioned earlier, barely nudged out these extra turn cards as a win condition. Extra turns can win games but not by themselves. They need cards like Warlock Class in order to win the game. 

+1/+1 Counters

Mikaeus the Unhallowed gives our creatures undying. When they die, they will come back to the battlefield with +1/+1 counters on them. These creatures serve the same purpose just like Wizard Class +1/+1 counters mentioned above. This will buff up our board. This can turn some incidental damage into significant damage. Mikaeus also combos with Triskelion, and it is an easy inclusion in this deck as well. You can read about the Mike and Trike Combo here. Mike and Trike is one of several ways to win the game. If you can win with it, then that’s great. What it does do is provide a focus on removal that is outside your value engine of Toxrill and proliferation. If we can keep the value engine intact, then we will find it easier to win the game. 

Insane Mana 

Proliferate provides multiple ways for us to increase our mana generation. For a small initial investment in mana, the deck can grow its mana production as the game continues on. When we proliferate, we will be wanting to do so for the other benefits on our board. When the opportunity arises, to add additional counters to Astral Cornucopia, Black Market, or Everflowing Chalice is pure value. Additional mana to proliferate other counters on our battlefield is essentially free and an advantage to us. These cards will give us mana in chunks.

Creatures should be dying left and right, so Black Market should generate significant mana for you on its own. To add counters by proliferate should allow you to have the mana for some significant explosive turns. Astral Cornucopia and Everflowing Chalice only need one counter to start the mana ramp, and any additional proliferate counters grow to be a value over time through the end of the game. If there is one mana generating counter, then we can proliferate. 

Did you consider…

How often do you see a home for storage lands?

Often overlooked are storage lands. These lands often enter the battlefield tapped and when you choose not to untap them they gain a storage counter. This seems like a bad deal because you are delaying mana now that can develop your board. Then, in return, you use that mana to develop your board later. However, these lands can be quite useful when you can properly manage your resources. Magic is a game about managing resources. If you can do that well, then you are in a better situation to win. With just one counter you can proliferate another. At worst the storage land functions as if it was a basic land. 

You can choose your times where you do not untap your storage lands. This allows them build up an additional counter. Since our deck is not playing at flash speed, it will be easier to plan out whether or not the mana is needed. These cards will allow you to have explosive turns commander decks use to win games. Even if you untap your storage land when you don’t need to, it can tap on the end step before your turn. Choose not to remove and storage counters from the card. Then you can put an additional counter on the card. 

Abusing Slugs

As you have read there are many different ways to proliferate and create value in the deck. The deck is not all in on any one strategy, but that you can pick and choose or even adapt to what you draw to build a value engine that can win you the game. You can accomplish this after you start clearing the battlefield using Toxrill. This is whether or not you were able to put the Sludge Monster in play. 

Not to be forgotten is that you will also be generating slug tokens while killing creatures. These tokens can create incidental attack damage or can be sacrificed for two mana to draw a card. Two mana is a little higher than the 1.5 mana we would prefer to spend to draw a card. Still, it’s card draw when you need it and there should be plenty of these tokens lying around as the game progresses. Also included in the deck is Skullclamp. The slugs are 1/1 creatures and for equipping Skullclamp to your slugs they will die. One mana for two cards is a better rate of return and justifies the inclusion in this deck.  

Summing It Up

There are a lot of little synergies in this deck that work together. For example you can use Sheoldred, Whispering One to bring back Sidisi, Undead Vizier. Then you can use Sidisi to exploit itself to bring any card to your hand. Then do it over again next turn. There also is an insane amount of card draw. Then you can get the cards you need to make a high mana value commander work as a deck. Due to Toxrill being a seven mana commander, you will be spending your early turns setting up for Toxrill. Then once you begin controlling the board, you can play out our larger threats and value engine pieces.

It may not seem so but giving your commander hexproof or shroud is important. However, one way to combat a deck with high mana value commanders is to remove them often enough so that it becomes too expensive to cast. So take that strategy away from them and force them to deal with your deck in other less obvious ways. 

Toxrill will take care of most creatures. For cards like Karn Liberated, Lux Cannon, and Tidespout Tyrant use them to take out enchantments first in most cases. Enchantments are difficult to remove and they provide value for the caster over time. By removing these enchantments, it will allow your value engine to surge ahead. That gives you an advantage so that you can win the game. 

There is a temptation since Urborg, Tomb of Yawgmoth is already in the deck to include Kormus Bell. The combination of cards will turn all your opponents lands into 1/1 creatures. From there a single end step with Toxrill will wipe away all your opponents lands. This is devistating but not included in the deck. This sort of combination of mass land destruction flies against the social contract of EDH. For that reason, it was not included in the deck. However, if you play in a high powered meta or a meta that capitalizes lack of land destruction using landfall, then by all means include it in the deck.

Final Words

The deck is not inexpensive as it uses a variety of staples for maximum efficiency. Cards like Rhystic Study, Necropotence, The Meathook Massacre and Toxic Deluge may not be necessary at some commander tables. You may replace them with more cost friendly options. The Tutors are expensive as well and are the most efficient in their color. Diabolic Tutor, Increasing Ambition, and Mastermind’s Acquisition are other budget options for the deck. Use them in early builds of the deck. Then add in the more expensive tutors as you can afford them. Finally, while it’s wise to have an alternate win condition in the deck. The Mike and Trike combo is removable for other cost-friendly cards to make Toxrill a reality.

Toxrill can be an intimidating commander. Like most commander decks they are tailored by the owner who builds them. What other cards would you use in your Toxrill deck? What exciting Synergies have you come up with? Commander Clinic wants to know. Leave a comment below. Also if you have any questions at all you can email us at you can find the decklist below. If you would like a visual list feel free to check out the deck on

Quick Deck list


Toxrill, the Corrosive


  • Crypt Ghast
  • Deepglow Skate
  • Echo Mage
  • Enclave Cryptologist
  • Flux Channeler
  • Hada Spy Patrol
  • Lighthouse Chronologist
  • Mikaeus, the Unhallowed
  • Sheoldred, Whispering One
  • Sidisi, Undead Vizier
  • Skithiryx, the Blight Dragon
  • Sludge Monster
  • Thrummingbird
  • Tidespout Tyrant
  • Triskelion
  • Viral Drake


  • Jace, Unraveler of Secrets
  • Karn Liberated
  • Liliana of the Dark Realms
  • Liliana, Dreadhorde General
  • Narset, Parted of Veils
  • Tamiyo the Moon Sage
  • Teferi, Master of Time


  • Black Market
  • Inexorable Tide
  • Necropotence
  • Rhystic Study
  • The Meathook Massacre
  • Training Grouds
  • Warlock Class
  • Wizard Class


  • Demonic Tutor
  • Drawn From Dreams
  • Grim Tutor
  • NIght’s Whisper
  • Read the Bones
  • Sign in Blood
  • Tezzeret’s Gambit
  • Torment of Hailfire
  • Toxic Deluge


  • Cyclonic Rift
  • Fact or Fiction
  • Impulse
  • Infernal Grasp
  • Mystical Tutor
  • Vampiric Tutor


  • Arcane Signet
  • Astral Cornucopia
  • Contagion Clasp
  • Contagion Engine
  • Dimir Signet
  • Everflowing Chalice
  • Lightning Greaves
  • Lux Cannon
  • Magistrate’s Scepter
  • Midnight Clock
  • Mind Stone
  • Skullclamp
  • Sol RIng
  • Swiftfoot Boots
  • Sword of Truth and Justice
  • Talisman of Dominence
  • Unwinding Clock


  • Bottomless Vault
  • Cabal Coffers
  • Command Tower
  • Dreadship Reef
  • Drowned Catacomb
  • 10 Island
  • Karn’s Bastion
  • Morphic Pool
  • Nykthos, Shrine to Nyx
  • Sand Silos
  • 13 Swamp
  • Temple of Deceit
  • Urborg, Tomb of Yawgmoth
  • War Room
  • Watery Grave

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