Breed Lethality precon upgrade guide

Four spells in this box sweep the creature board and 28 creatures are what they sweep, so the upgrade starts with the sweepers and the mana before it touches the counters.

Atraxa, Praetors' Voice is a 4/4 flier with vigilance, deathtouch and lifelink that proliferates at the beginning of your end step. The box builds around her with 27 other creatures and a long run of cards that put +1/+1 counters on them, then packs Languish, Merciless Eviction, Duneblast and Sublime Exhalation in beside them. Languish gives every creature -4/-4, so Atraxa herself dies to it unless a counter is already on her. Sublime Exhalation says {6}{W} but has undaunted, which makes it {3}{W} against three opponents, and it destroys every creature.

Two more cards hurt the board that owns them. Necroplasm destroys each creature whose mana value equals its own counter total at your end step, yours included, and Bane of the Living turns face up for {X}{B}{B} and gives every creature -X/-X. Against that, the box answers a single creature with Mortify and Putrefy, both three mana, and has no cheap exile.

Three more numbers shape the swaps. Seven lands arrive tapped: six always do, and Murmuring Bosk enters tapped unless you reveal a Treefolk, which this box doesn't contain. Only two cards besides Atraxa proliferate, Thrummingbird and Tezzeret's Gambit. And there are seven mana rocks, for an average mana value of 3.7. Everything below is measured on the shipped decklist, and "stock" means the box as printed.

Which Breed Lethality upgrades come first?

In order of how much each one fixes a problem the box has. Prices are October 2026 market prices at the cheapest released printing, so a few are promo or reprint-set copies.

1. Swords to Plowshares ($1.07). One white mana, exiles a creature at instant speed. The box answers a single creature with two three-mana spells and nothing cheaper.
2. Anguished Unmaking ($1.64). {1}{W}{B}, exile any nonland permanent, lose 3 life. It exiles, so persist and recursion don't matter, and it hits planeswalkers and any other nonland permanent. Atraxa's lifelink wins the life back.
3. Evolution Sage ($2.08). Proliferate on every land that enters under your control, in a deck with 39 lands. Details in the proliferate section.
4. Winding Constrictor ($0.45). {B}{G} for a creature that adds one more counter of each kind to your creatures and artifacts. It takes the box's two multipliers from four counters to six.
5. Hallowed Fountain ($7.13) and Breeding Pool ($9.16). Two lands that enter untapped for 2 life, replacing the two bounce lands. Fountain taps for white or blue and Pool for green or blue, and blue and white are the colours that are short.
6. Flux Channeler ($2.65). Proliferate whenever you cast a noncreature spell, and 30 of the deck's cards are.
7. Cultivate ($0.39). Two basics for {2}{G}, one onto the battlefield and one to hand. Here they're an Island and a Plains.
8. Arcane Signet ($0.34). Two mana for any colour in Atraxa's identity, which is all four.
9. Grateful Apparition ($0.18). A two-mana 1/1 flier that proliferates when it connects.

That is ten adds for $25.09. The cuts they replace are in the next section.

The fourth sweeper and nine more cuts

Sublime Exhalation goes first. It costs as little as Languish in a four-player pod, but it's the only one that can't spare anything. Duneblast destroys every creature except one you choose as it resolves, and that choice doesn't target, so it can protect Atraxa or whichever creature carries the most counters. Languish leaves anything with toughness above 4 standing. Merciless Eviction can exile artifacts, enchantments or planeswalkers instead of creatures, so it answers boards that aren't made of creatures. Those three each do something the fourth doesn't.

The deck is built to live through them anyway. Reveillark returns up to two creature cards with power 2 or less when it leaves the battlefield, and Reyhan, Last of the Abzan puts the +1/+1 counters of any creature that dies onto a target creature. Run Duneblast with Reyhan out and the survivor collects the counters from every creature that died with +1/+1 counters on it, including creatures that went in the same sweep as Reyhan. That is what the sweepers are for in this box, and Sublime Exhalation can't join in because it leaves no survivor to receive anything.

Most of the other nine do nothing for a counters deck, or cost too much to do it. Spitting Image makes a token copy of a creature for six mana and can be retraced, but the copy doesn't copy counters, and counters are the whole currency here. Mirrorweave turns every other creature, yours included, into a copy of one nonlegendary creature until end of turn. Counters aren't copied and stay where they are, so it's a trick that works no better for a counters deck than for any other, and it can make your own board worse for a turn. Ancient Excavation draws cards equal to your hand and discards the same number, so it nets zero cards for four mana and is in the box mostly for its landcycling. Cauldron of Souls costs five to give creatures persist, and a creature that persists comes back as a new object with a -1/-1 counter and none of what it earned. Deepglow Skate doubles counters once, on arrival, for five mana, while Vorel of the Hull Clade, which stays, does it every turn for {G}{U} and a tap.

Brave the Sands gives vigilance and extra blocks to a deck whose commander already has vigilance. Duelist's Heritage gives double strike to one attacker each combat, which only pays if that attacker was going to connect. The last two cuts are the lands, and they belong to the next section.

The five-drops that earn their mana

The upgraded deck still has ten cards at five mana, down from twelve, and I looked at each. Cathars' Crusade is the one that surprises people. Each creature that enters under your control puts a +1/+1 counter on every creature you control, and the box's multipliers apply to each of those counters. Citadel Siege costs four, and its Khans mode puts two counters on a creature at the start of every combat of yours, which becomes six with Hardened Scales and Corpsejack Menace out. Elite Scaleguard bolsters 2 on arrival and then taps a defending creature whenever a creature of yours with a counter attacks. Juniper Order Ranger puts a counter on itself and on each creature that enters after it. Vulturous Zombie grows whenever a card goes to an opponent's graveyard from anywhere, and in a four-player pod three graveyards feed it.

Ghave, Guru of Spores is the slowest of them. It enters with five counters, turns one into a 1/1 Saproling for {1}, and sacrifices a creature for a counter on a target creature. I kept it because a creature that's about to die becomes a counter on the survivor, and with Corpsejack Menace out that counter lands as two.

Seven tapped lands become five

Stock, six lands always enter tapped (Arcane Sanctum, Azorius Chancery, Golgari Rot Farm, Opulent Palace, Sandsteppe Citadel and Seaside Citadel) and Murmuring Bosk joins them when no Treefolk is in hand. That's seven in a 39-land deck. The four triomes stay, since each taps for three of Atraxa's four colours. The two bounce lands go, which is the closest call in this list: a bounce land taps for two mana once it's down, and every replayed land is another landfall for Evolution Sage. I cut them because the colours this deck is short of are needed early, and a land that enters tapped and takes a land back off the table works against that on turns two to four. Azorius Chancery becomes Hallowed Fountain and Golgari Rot Farm becomes Breeding Pool. Playing either one untapped costs 2 life, and they arrive tapped otherwise, which leaves five lands that always or usually enter tapped: the four triomes and Murmuring Bosk.

Fountain taps for white or blue where Chancery made both at once, so the white and blue counts don't change. Pool taps for green or blue where Rot Farm made black and green, which moves one source from black to blue. Arcane Signet adds a source of all four colours. The net, as the analysis counts it, is black 25 to 25, green 25 to 26, blue 22 to 24 and white 22 to 23. Those counts are generous. They credit Fellwar Stone and Exotic Orchard with every colour although both depend on what opponents control, and they credit Darkwater Catacombs, Sungrass Prairie and Opal Palace although each needs {1} from another land first. Treat each number as a ceiling.

Blue now meets the 24 sources a one-pip two-drop wants at 90%, and white is one short at 23. Blue's double-pip problem goes away because the two cards that wanted UU, Mirrorweave and Spitting Image, are cut. The other double-pip cards stay awkward. Languish, Necroplasm and Bane of the Living want BB by turn three, and black has 25 sources for about a 72% chance. Champion of Lambholt and Kalonian Hydra want GG at 26 sources for about 74%, and Cathars' Crusade and Citadel Siege want WW by turn four at 23 sources for about 73%. Cultivate isn't counted as a source, but it fetches the Island or Plains you're missing. Breeding Pool and Hallowed Fountain are both reprinted in Star Trek on 13 November 2026, so their prices may drop, and if you aren't in a hurry that is a reason to buy them last.

Proliferating on your own turn

Atraxa's trigger comes at the end step, after combat, so the counters it adds can't help the attack you just made. Three of the adds fire on your terms instead. Evolution Sage proliferates whenever a land enters under your control. Evolving Wilds and Terramorphic Expanse each count twice, once when the fetch land enters and once when the basic it finds does, and Cultivate puts one land onto the battlefield and another in your hand to play, which is two more. Flux Channeler proliferates when you cast a noncreature spell, and its trigger resolves before the spell, even if the spell is countered. Grateful Apparition proliferates when it deals combat damage to a player. With those, six cards proliferate where the box had three.

The multipliers are where the numbers get large. Hardened Scales adds one counter to +1/+1 counters going onto your creatures, and Corpsejack Menace doubles them. You choose the order, so the best order adds first and doubles last. One counter from proliferate becomes (1 + 1) × 2 = 4 with the box's pair, and (1 + 1 + 1) × 2 = 6 once Winding Constrictor is out. Fathom Mage draws a card whenever a +1/+1 counter is put on it, and it triggers once per counter. Once it has a counter of its own, an end-step proliferate that includes it can draw four cards with the pair and six with Constrictor.

Doubling Season and the other cards left in the cart

The ten adds cost $25.09. The next buy would be Doubling Season ($29.95), which doubles counters and tokens, so it also doubles the four Birds from Migratory Route. I left it out because the deck already has two multipliers and gets a third in Winding Constrictor, so a fourth adds less than the first three did, and the lands fix a problem the box actually has. Rhystic Study ($67.12) would fill the draw gap, but it's on the Game Changers list, which no card in this deck is today. Path to Exile ($0.93) does Swords' job, and once Swords and Anguished Unmaking are in, a third cheap exile effect isn't what the box lacks.

The gap I didn't close is card draw. The box draws with Fathom Mage, Treasure Cruise, Tezzeret's Gambit, Manifold Insights, Inspiring Call, Bred for the Hunt and the sacrifice on Commander's Sphere, and none of my ten adds draws a card. Fathom Mage under the multipliers is the strongest draw engine in the list, so keep it alive.

The upgraded decklist

The list below is the box after all ten swaps, 100 cards with Atraxa in the command zone. Hover any name for the card, and prices follow the same cheapest-printing rule as above.

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“Load into the deck builder” opens this list in your account, pinned to the printings the box shipped, ready to edit or save. “Copy decklist” gives you plain text for Moxfield, Archidekt or Arena, with no account needed.

FAQ

Does Languish kill my own Atraxa?

Yes, unless she has a +1/+1 counter on her. Atraxa is a 4/4 and Languish gives every creature -4/-4 until end of turn. Proliferate can only add a counter to a permanent that already has one, so it won't start her off. Duneblast lets you pick one creature to spare, and that choice doesn't target, so it can be Atraxa. Merciless Eviction in its creature mode exiles every creature.

Is this the same deck as Breed Lethality from Commander 2016?

Yes. I compared the two lists card by card, and all 100 cards match. The differences are the printings (this one uses Commander Anthology Volume II's collector numbers, Atraxa included) and how you can buy it: this one was only sold in the four-deck Commander Anthology Volume II box, which cost $164.99 ($41.25 a deck), while the 2016 version was a standalone deck. Singles come to roughly $154 for this list against $139 for the 2016 one as of mid October 2026. The 2016 guide argues from proliferate first and shares some of its swaps with this one. This guide argues from the sweepers and the mana.

How much do the upgrades cost?

$25.09 for ten adds at the cheapest released printing, as of October 2026. Hallowed Fountain ($7.13) and Breeding Pool ($9.16) are $16.29 of it, and the other eight come to $8.80. None of the adds is on the Game Changers list.

Will Hallowed Fountain and Breeding Pool get cheaper?

They might. Both are reprinted in Star Trek on 13 November 2026. If you don't need the lands next week, wait and check the price again. The other eight adds are cheap enough that I wouldn't wait on them.

How many cards can Fathom Mage draw off one proliferate?

Up to four from the box as printed, and six with Winding Constrictor. Fathom Mage draws once for every +1/+1 counter put on it, and the box already has Hardened Scales and Corpsejack Menace. One proliferate adds a counter, Hardened Scales makes it two, Corpsejack Menace doubles that to four, and Constrictor adds one before the doubling. Fathom Mage needs a counter on it already, or proliferate has nothing to add to.

Should I keep all four wraths if my pod is mostly creatures?

I'd keep three. Languish, Duneblast and Merciless Eviction each do something different, and Duneblast is the one that works with Reyhan. Sublime Exhalation is the cheapest, {3}{W} against three opponents, but it destroys your creatures with no survivor. If your pod rarely commits creatures early, it's the first one back in.