Tyranid Swarm precon upgrade guide

Twelve cards in this box cost X. Eleven of them are Ravenous creatures that draw a card once X reaches five, and two more, Nexos and Magus Lucea Kane, are built around paying for it.

The Swarmlord pays off something else: a creature with a counter on it dying. The box is full of creatures carrying counters and has exactly one way to kill one on purpose, which is Tyrant Guard sacrificing itself. So the upgrade has two jobs. Make X bigger, and give the deck somewhere to put its creatures once they've done their work.

What are the best Tyranid Swarm upgrades?

Nine entries, and the first two are the two jobs above, one card each:

1. Unbound Flourishing ($2.43). It doubles X on every Ravenous creature, so one cast with X of three enters as six and draws the card. It also copies Starstorm.
2. Ashnod's Altar ($15.67). Sacrifice a creature, add two colourless. If that creature had a counter on it, The Swarmlord draws you a card, and colourless mana is exactly what an X cost wants.
3. Rootbound Crag, Hinterland Harbor and Sulfur Falls ($0.94 together). Always-tapped lands go from seven to four. Why these three and not the painlands is further down, and it's the most important paragraph on the page if you own a Ghyrson Starn.
4. Branching Evolution ($7.55). Twice as many +1/+1 counters, every time. Next to Hardened Scales, a Ravenous creature cast with X of five enters with twelve. Doubling Season does the same and doubles tokens as well, and at $33.30 it's the next card I'd buy rather than the first.
5. Walking Ballista ($10.56). A thirteenth X card, and every counter it spends is 1 damage, which Ghyrson Starn turns into 3.
6. Rosheen Meanderer ($0.37). Four mana a turn, spendable only on X costs, which in this deck is barely a restriction.
7. Goblin Bombardment ($2.61). The second sacrifice outlet, and the one that ends games next to Ghyrson.
8. Beast Within ($0.61), Rapid Hybridization ($1.05) and Ram Through ($0.54). Instant-speed answers, in a box whose only creature removal is attached to creatures.
9. Heroic Intervention ($15.96). Tyrant Guard protects the creatures with counters. This protects the tokens too.

Thirteen cards come out to make room. They're listed below, with the ones I kept.

Eleven Ravenous creatures, and the card draw starts at five

Ravenous means the creature enters with X +1/+1 counters, and if X is five or more you draw a card as it enters. Eleven creatures in the box have it: Exocrine, Broodlord, Hormagaunt Horde, Sporocyst, Termagant Swarm, Tervigon, Tyrant Guard, Mawloc, Ravener, Zoanthrope and Aberrant. Add Starstorm and twelve cards cost X.

Five is a lot of mana to put into X on top of a creature's printed cost. Tervigon at five is seven mana. Broodlord at five is nine. So the box brings help, and it's good help. Nexos gives every basic land “{T}: Add {C}{C}” for costs containing X, and there are twenty-two basics. Magus Lucea Kane taps for two and copies the next X spell you cast that turn. The First Tyrannic War puts a creature from your hand onto the battlefield with a counter for every land you control, as long as its cost has an X in it.

Two of the adds push the same direction. Rosheen Meanderer taps for four toward X costs. Unbound Flourishing is the better card: whenever you cast a permanent spell with X in its cost it doubles X, and the Ravenous check reads the doubled number. Termagant Swarm cast with X of three enters with six counters and draws. Walking Ballista costs {X}{X}, so under Unbound Flourishing it enters with twice the counters you paid for.

One number to read carefully. The upgraded deck's average mana value is 3.07, down from 3.32 in the box, and both figures flatter it. Mana value counts X as zero, so Hormagaunt Horde, Termagant Swarm and Sporocyst sit in the curve as one-drops and Walking Ballista as a zero. None of them is ever cast for that.

It's also the case for the thirty-nine lands, which I left alone. That's above the thirty-five to thirty-eight a hundred-card deck usually wants, and in a deck where every spare land becomes a bigger X, flooding mostly means your next Tervigon is larger.

The Swarmlord draws off deaths the box can't cause

Xenos Cunning draws a card whenever a creature you control with a counter on it dies. Plenty of creatures qualify: all eleven Ravenous ones, Purestrain Genestealer, anything Tyranid Prime's evolve has grown, and whatever Magus Lucea Kane put a counter on this combat.

What the deck lacks is a way to make them die when you want. Harrow, Evolving Wilds, Terramorphic Expanse and Cave of Temptation all sacrifice lands. Old One Eye discards cards. The only card in the ninety-nine that sacrifices a creature is Tyrant Guard, and the creature it sacrifices is itself. Every other card The Swarmlord draws depends on combat or on an opponent's removal.

Death's Presence has the same problem from the other end. It's six mana to put counters on a creature when another one dies, in a deck that can't kill its own. It's the first cut.

Ashnod's Altar and Goblin Bombardment fix it. Each one turns a creature into something: two colourless mana from the Altar, 1 damage from Bombardment, and a card from The Swarmlord either way if the creature carried a counter. Termagant Swarm is the one to watch. When it dies it makes 1/1 Tyranid tokens equal to its power, so a Termagant cast with X of five and fed to the Altar is two mana, a card, and five fresh bodies to feed it next.

The Ozolith keeps the counters from every creature of yours that leaves the battlefield and moves them onto another at the start of combat. It was built for this commander. At $66.00 it also costs more than this whole list, which is the only reason it isn't on it.

Ghyrson Starn turns every point of 1 damage into 3

Ghyrson Starn, Kelermorph costs $36.29 on its own, more than half of this entire upgrade list, and the reason is one line of text. Whenever another source you control deals exactly 1 damage to a permanent or player, Ghyrson deals 2 more to it.

The box has a handful of sources that deal exactly 1. The 1/1 tokens from Termagant Swarm, Tervigon, Gargoyle Flock and Tyranid Harridan each deal 1 in combat, so an unblocked token is 3 damage. Two of the adds are built to exploit it. Goblin Bombardment deals 1 per creature sacrificed, so with Ghyrson out every creature you feed it is 3 damage to any target, and a board of eight tokens is 24. Walking Ballista's counters each ping for 1, and each ping becomes 3.

There's a tension here worth knowing about. Everything else in this deck wants creatures bigger, and a token with a counter on it deals 2 damage, not 1. Ghyrson rewards the tokens you haven't grown yet. Goblin Bombardment is how you cash in any creature at exactly 1, whatever its size.

Checklands, because Ghyrson reads a painland as damage

The three tapped lands I cut are Rugged Highlands, Thornwood Falls and Temple of Abandon. The obvious untapped replacements in these colours are the painlands, Karplusan Forest, Yavimaya Coast and Shivan Reef, all well under a dollar. Don't. A painland deals 1 damage to you when it taps for coloured mana, and that is exactly 1 damage from a source you control. With Ghyrson Starn on the battlefield, every coloured tap costs you 3 life.

Rootbound Crag, Hinterland Harbor and Sulfur Falls cost about the same and enter untapped if you control a land of either of their basic types. Twenty-two basics, plus Cinder Glade, which is both a Mountain and a Forest, make that close to automatic from turn two. Always-tapped lands fall from seven to four.

Blue was the colour I watched. It has 22 sources in the box, and a one-pip blue spell by turn two comes out 87.7% of the time, a little under the 90% I'd want. New Horizons counted as a source of every colour, so cutting it costs one of each, and Sulfur Falls replaces Temple of Abandon to hold blue at 22. Green pays for that: 25 sources, down from 27. A single green pip still clears the bar at 91.2%. Abundance and Hierophant Bio-Titan, the two cards that want {G}{G} by turn four, fall from 81.8% to 77.7%, and Hierophant is a card you cast late anyway. Starstorm is the only card that wants {R}{R}, and it cycles for {3} when red isn't there.

The four that still enter tapped each earn something. Temple of Epiphany and Temple of Mystery scry. Frontier Bivouac makes all three colours. Path of Ancestry scries whenever its mana casts a creature that shares a type with The Swarmlord, which is 32 of the 34 creatures after these swaps.

Every creature answer in the box is attached to a creature

Count the ways Tyranid Swarm can kill one specific creature an opponent controls. Mawloc fights one when it enters. Zoanthrope deals X damage to any target when it enters. Screamer-Killer deals 5 to any target whenever you cast a creature spell with mana value five or more, and a Ravenous spell's mana value on the stack includes X, so a Tervigon cast with X of three sets it off. That's the list. Hull Breach and Aberrant handle artifacts and enchantments, and Starstorm and Exocrine hit every creature, yours included.

Three creatures is removal that dies to removal, and none of it works at instant speed. Beast Within kills any permanent for three mana. Rapid Hybridization kills a creature for one. Both leave the opponent a 3/3, which is a fair price in a deck whose creatures are routinely bigger than that. Ram Through suits this deck best: your creature deals damage equal to its power to theirs, and if yours has trample the excess goes to the player. Old One Eye gives every other creature you control trample, and Tervigon and Aberrant have it already.

Aetherize comes out for them. It returns attacking creatures to their owners' hands, which is a good card for a deck being attacked and the wrong one for a deck that wins by attacking.

Heroic Intervention is the other half. Tyrant Guard already hands out hexproof and indestructible for a turn, but only to creatures with counters on them, and the tokens from Termagant Swarm, Tervigon, Old One Eye and Tyranid Invasion don't have any. Heroic Intervention covers every permanent you control for two mana. At $15.96 it's the dearest card on the list and the last one I'd buy, because Tyrant Guard already does most of its job.

Ten cards leave, and Clamavus isn't one of them

Death's Presence and Aetherize are argued above, and the three lands have their own section. The rest:

• Genestealer Patriarch (5). A 4/4 whose payoff needs an infected creature to die, and the infection only goes on when it attacks.
• Genestealer Locus (4). A 3/3 whose text moves combat by a point in each direction.
• Acolyte Hybrid (3). Artifact removal that gives the artifact's owner a card back.
• Goliath Truck (4). Crew 2 to put two counters on another attacker. Bone Sabres puts four on the creature carrying it, on every attack.
• Lictor (4). The 3/3 token only arrives if a creature entered under an opponent's control that turn. Otherwise it's a 3/3 for four.
• Malanthrope (3). A 2/2 flier that exiles a graveyard. It's also the only graveyard answer in the box, so if your pod has a reanimator player, keep it over Ram Through.
• Explore (2). A second land drop and a card, in a deck already running Cultivate, Farseek, Rampant Growth and Harrow.
• New Horizons (3). One counter and one extra mana a turn. Overgrowth, the other land Aura, adds two extra, and both of them green, the colour with the double-pip demand.

Clamavus looks like a five-drop with no job, and it's closer to the reverse. Each creature you control gets +1/+1 for every +1/+1 counter on it, which doubles the size of everything this deck grows. With Branching Evolution out as well, each counter you'd have placed is worth +4/+4.

The First Tyrannic War costs five and reads like a slow saga. Chapter one puts a creature from your hand onto the battlefield, and if it has X in its cost it enters with a counter for each land you control. In a thirty-nine-land deck that's a Ravenous creature at six or seven counters without paying for X. It won't draw the Ravenous card, because nothing was cast. Chapters two and three each double every kind of counter on a creature.

Magus Lucea Kane only buffs one creature a combat, and that isn't why it's here. It taps for two and copies the next X spell, and a copied Ravenous creature spell becomes a second creature with the same X.

Bone Sabres is one Equipment in a deck of thirty-odd creatures, and it still stays. It puts four counters on the attacker every time, and with Hardened Scales and Branching Evolution that's up to ten.

Hierophant Bio-Titan has a printed cost of twelve. It costs two less for each +1/+1 counter you remove from your creatures while casting it, so taking off five brings it down to {G}{G}.

The upgraded decklist

All thirteen swaps made, a hundred cards in total. Each name opens its card on hover, with today's price.

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FAQ

Which creature type should I name with Herald's Horn and Icon of Ancestry?

Tyranid, and there's no real choice to make. Every one of the 37 creatures in the box is a Tyranid, so Herald's Horn, Icon of Ancestry and Unclaimed Territory all cover the whole deck. After these swaps it's 32 of 34. The two that miss out are Rosheen Meanderer and Walking Ballista, which don't get the Horn's discount or the Icon's +1/+1 and can't use Unclaimed Territory's coloured mana.

How many counters does a Ravenous creature get with Hardened Scales and Branching Evolution out?

Apply Hardened Scales first and Branching Evolution second, and a Ravenous creature cast with X of five enters with twelve: five, plus one, doubled. The other order gives eleven, and you're the one who chooses. Add Unbound Flourishing and that same five becomes ten before either enchantment sees it, so the creature enters with twenty-two. It draws its card either way.

How does Tyranid Swarm play with no changes at all?

Better than its seven tapped lands suggest. The mana is deep, with thirty-nine lands, four land-search spells, two rocks and Nexos, and eleven Ravenous creatures give all of it somewhere to go. What the box doesn't do is interact. Three creatures can kill one opposing creature, nothing at instant speed can pick a single target, and nothing protects a board of tokens from a sweeper. Those two gaps are what most of the adds are for.

What do the thirteen swaps cost?

$58.29 in total, priced on 11 September 2026 from each card's default printing at TCGplayer market.Heroic Intervention ($15.96), Ashnod's Altar ($15.67) and Walking Ballista ($10.56) are $42.19 of it, and the other ten come to $16.10. The three checklands are 94 cents between them. The two cards I priced and left off are Doubling Season at $33.30 and The Ozolith at $66.00.

Does Unbound Flourishing let a Ravenous creature draw for a smaller X?

Yes. It doubles X when the spell is cast, and the Ravenous check reads that doubled number as the creature enters. Cast any of the eleven with X of three and it enters with six counters and draws. It does nothing for The First Tyrannic War, because putting a creature onto the battlefield isn't casting it.

Could Magus Lucea Kane lead this deck instead of The Swarmlord?

It could, and the ninety-nine wouldn't need to change much. Magus Lucea Kane is four mana in the same three colours, taps for two, and copies an X spell once a turn, which is a stronger engine for eleven Ravenous creatures than anything The Swarmlord does. What you give up is the card draw when creatures with counters die, and a commander who arrives bigger every time he's recast. The Swarmlord still works in the ninety-nine, because Rapid Regeneration counts casts of your commander, whichever card that is.

Why keep thirty-nine lands in a deck with this much ramp?

Because every spare land becomes a bigger X. Thirty-nine is above the thirty-five to thirty-eight most hundred-card decks run, and in most decks a land off the top late in the game is a dead draw. Here it's another counter on Tervigon, or the fifth mana that gets a Ravenous creature to draw. Hormagaunt Horde even climbs back into your hand whenever a land enters, for {2}{G}. And twenty-two of the lands are basics, which Nexos turns into two mana each for X costs.