Kalamax, the Stormsire costs {1}{G}{U}{R} and is a 4/4 Legendary Elemental Dinosaur. Whenever you cast your first instant spell each turn, if Kalamax is tapped, you copy that spell and may choose new targets for the copy, and whenever you copy an instant spell Kalamax gets a +1/+1 counter. The key phrase is "if Kalamax is tapped," so tapping Kalamax before you cast an instant is what makes the deck work.

The precon already has the instants and the ramp, including Growth Spiral, Harrow, Wilderness Reclamation, Frantic Search and Twinning Staff. Each swap below pairs a cut with an add, and every card is scored with the same numbers the Oracle uses to build decks: synergy and inclusion from the Kalamax decks, plus lift, which shows how much more often a card turns up in Kalamax decks than in decks that could play it.

Looking for the unmodified list first? Read the Arcane Maelstrom precon guide.

12
Swaps
$9.97
Cost of the adds
38→38
Lands
0→45
Avg Oracle score

What is holding the deck back

Not enough ways to tap Kalamax and copy spells

Springleaf Drum taps an untapped creature, such as Kalamax, for mana at instant speed. Reverberate, Increasing Vengeance, Narset's Reversal and Expansion copy spells, and Goblin Electromancer and Archmage Emeritus reward the spells. They are among the top-scoring cards the precon leaves out.

Clunky instants outside the lists

Channeled Force, Chemister's Insight, Clash of Titans, Commune with Lava, Curious Herd, Decoy Gambit, Hunting Pack, Starstorm, Strength of the Tajuru and Whiplash Trap are not cards Kalamax decks usually play.

Rocks outside the lists

Bonder's Ornament is not a card Kalamax, and Djinn Illuminatus is a seven-drop decks usually play. The deck has 8 nonland cards at mana value six or more.

The 12 swaps

Each pair shows the numbers for the card coming out and the card going in. Click a card image to zoom.

Swap 1 of 12
Channeled Force
Cut
Channeled Force
Instant · 2UR
Not a card this commander's decks usually play, so it scores below the cards that are
Big Score
Add
Big Score
Instant · 3R
Inclusion50%
Synergy44%
Lift7.7×
Oracle score 46

Channeled Force is a four-mana instant that discards X cards to draw X cards and deal X damage. It is not a card Kalamax decks usually play.

Big Score costs {3}{R}, with an additional cost of discarding a card. You draw two cards and create two Treasure tokens. A four-mana instant that replaces itself and pays for the next spell.

Swap 2 of 12
Chemister's Insight
Cut
Chemister's Insight
Instant · 3U
Not a card this commander's decks usually play, so it scores below the cards that are
Opt
Add
Opt
Instant · U
Inclusion46%
Synergy39%
Lift7.4×
Oracle score 42

Chemister's Insight is a four-mana instant that draws two cards, with jump-start. It is not a card Kalamax decks usually play.

Opt costs {U}. You scry 1, then draw a card. A one-mana instant that is the cheapest way to make a first instant each turn, so Kalamax copies it.

Swap 3 of 12
Clash of Titans
Cut
Clash of Titans
Instant · 3RR
Not a card this commander's decks usually play, so it scores below the cards that are
Soul's Fire
Add
Soul's Fire
Instant · 2R
Inclusion38%
Synergy36%
Lift8.0×+
Oracle score 37

Clash of Titans is a five-mana instant where one creature fights another. It is not a card Kalamax decks usually play.

Soul's Fire costs {2}{R}. Target creature you control deals damage equal to its power to any target. A three-mana instant where Kalamax's growing power does the damage, and the copy does it twice.

Swap 4 of 12
Commune with Lava
Cut
Commune with Lava
Instant · XRR
Not a card this commander's decks usually play, so it scores below the cards that are
Expansion // Explosion
Add
Expansion // Explosion
Instant // Instant · U/RU/R // XUURR
Inclusion39%
Synergy37%
Lift8.0×+
Oracle score 38

Commune with Lava is an {X}{R}{R} instant that exiles cards you may play. It is not a card Kalamax decks usually play.

Expansion // Explosion is a split instant. Expansion costs {U/R}{U/R} and copies target instant or sorcery spell with mana value 4 or less, and Explosion costs {X}{U}{U}{R}{R} and deals X damage to any target and makes a player draw X cards. A two-mana copy spell that is also a late-game finisher.

Swap 5 of 12
Curious Herd
Cut
Curious Herd
Instant · 3G
Not a card this commander's decks usually play, so it scores below the cards that are
Reverberate
Add
Reverberate
Instant · RR
Inclusion44%
Synergy43%
Lift8.0×+
Oracle score 43

Curious Herd is a four-mana instant that makes Beasts for each artifact an opponent controls. It is not a card Kalamax decks usually play.

Reverberate costs {R}{R}. It copies target instant or sorcery spell, and you may choose new targets for the copy. A two-mana instant that copies any spell, including an opponent's.

Swap 6 of 12
Decoy Gambit
Cut
Decoy Gambit
Instant · 2U
Not a card this commander's decks usually play, so it scores below the cards that are
Increasing Vengeance
Add
Increasing Vengeance
Instant · RR
Inclusion33%
Synergy31%
Lift8.0×+
Oracle score 32

Decoy Gambit is a three-mana instant that bounces creatures unless their controllers let you draw. It is not a card Kalamax decks usually play.

Increasing Vengeance costs {R}{R}. It copies target instant or sorcery spell you control, twice if it was cast from a graveyard, and has flashback {3}{R}{R}. A two-mana instant that copies your spell now and twice later.

Swap 7 of 12
Hunting Pack
Cut
Hunting Pack
Instant · 5GG
Not a card this commander's decks usually play, so it scores below the cards that are
Narset's Reversal
Add
Narset's Reversal
Instant · UU
Inclusion47%
Synergy43%
Lift8.0×+
Oracle score 45

Hunting Pack is a seven-mana instant with storm that makes 4/4 Beasts. It is not a card Kalamax decks usually play.

Narset's Reversal costs {U}{U}. It copies target instant or sorcery spell, then returns it to its owner's hand, and you may choose new targets for the copy. A two-mana instant that copies a spell and returns your own to hand.

Swap 8 of 12
Starstorm
Cut
Starstorm
Instant · XRR
Not a card this commander's decks usually play, so it scores below the cards that are
Archmage Emeritus
Add
Archmage Emeritus
Creature — Human Wizard · 2UU
Inclusion70%
Synergy59%
Lift6.4×
Oracle score 63

Starstorm is an {X}{R}{R} instant that deals X damage to each creature, including Kalamax, with cycling. It is not a card Kalamax decks usually play.

Archmage Emeritus is a 2/2 Human Wizard for {2}{U}{U}. Magecraft: whenever you cast or copy an instant or sorcery spell you draw a card. A four-drop that draws a card from every spell and every copy.

Swap 9 of 12
Strength of the Tajuru
Cut
Strength of the Tajuru
Instant · XGG
Not a card this commander's decks usually play, so it scores below the cards that are
Wavebreak Hippocamp
Add
Wavebreak Hippocamp
Enchantment Creature — Horse Fish · 2U
Inclusion42%
Synergy40%
Lift8.0×+
Oracle score 41

Strength of the Tajuru is an {X}{G}{G} instant that puts counters on creatures. It is not a card Kalamax decks usually play.

Wavebreak Hippocamp is a 2/2 Horse Fish enchantment creature for {2}{U}. Whenever you cast your first spell during each opponent's turn, you draw a card. A three-drop that draws a card from the instants you cast on their turn.

Swap 10 of 12
Whiplash Trap
Cut
Whiplash Trap
Instant — Trap · 3UU
Not a card this commander's decks usually play, so it scores below the cards that are
Goblin Electromancer
Add
Goblin Electromancer
Creature — Goblin Wizard · UR
Inclusion44%
Synergy36%
Lift5.3×
Oracle score 39

Whiplash Trap is a five-mana instant that bounces two creatures. It is not a card Kalamax decks usually play.

Goblin Electromancer is a 2/2 Goblin Wizard for {U}{R}. Instant and sorcery spells you cast cost {1} less. A two-drop that makes every instant cheaper.

Swap 11 of 12
Bonder's Ornament
Cut
Bonder's Ornament
Artifact · 3
Not a card this commander's decks usually play, so it scores below the cards that are
Springleaf Drum
Add
Springleaf Drum
Artifact · 1
Inclusion59%
Synergy53%
Lift8.0×+
Oracle score 56

Bonder's Ornament is a three-mana rock that taps for any color. It is not a card Kalamax decks usually play.

Springleaf Drum costs {1}. For a tap and tapping an untapped creature you control, you add one mana of any color. A one-mana artifact that taps Kalamax at instant speed, which is what turns on its copy trigger.

Swap 12 of 12
Djinn Illuminatus
Cut
Djinn Illuminatus
Creature — Djinn · 5U/RU/R
Not a card this commander's decks usually play, so it scores below the cards that are
Storm-Kiln Artist
Add
Storm-Kiln Artist
Creature — Dwarf Shaman · 3R
Inclusion67%
Synergy56%
Lift5.7×
Oracle score 60

Djinn Illuminatus is a seven-mana 3/5 flyer that gives your instants and sorceries replicate. It is not a card Kalamax decks usually play.

Storm-Kiln Artist is a 2/2 Dwarf Shaman for {3}{R}. It gets +1/+0 for each artifact you control, and magecraft: whenever you cast or copy an instant or sorcery spell you create a Treasure token. A four-drop that pays you a Treasure for every spell and copy.

The full swap list

Cut

  • Channeled Force
  • Chemister's Insight
  • Clash of Titans
  • Commune with Lava
  • Curious Herd
  • Decoy Gambit
  • Hunting Pack
  • Starstorm
  • Strength of the Tajuru
  • Whiplash Trap
  • Bonder's Ornament
  • Djinn Illuminatus

Add

  • Big Score
  • Opt
  • Soul's Fire
  • Expansion // Explosion
  • Reverberate
  • Increasing Vengeance
  • Narset's Reversal
  • Archmage Emeritus
  • Wavebreak Hippocamp
  • Goblin Electromancer
  • Springleaf Drum
  • Storm-Kiln Artist

What to keep

These cards are doing the deck's heavy lifting. Do not cut them.

If you want to spend more

These are strong but sit outside a budget upgrade. Prices are the cheapest paper printing.

The verdict

Arcane Maelstrom already has 25 instants, the ramp and the mana tricks. The upgrade is cheap instants, copy effects and Springleaf Drum to tap Kalamax, in place of clunky instants and cards that Kalamax decks leave out. These twelve swaps cost about $10 in total.

Want a full 100-card list built around Kalamax, the Stormsire from today's data?

Build with The Oracle →

Frequently asked questions

What are the best upgrades for the Arcane Maelstrom precon?

Using data from 8,812 Kalamax decks, the highest-scoring additions are Archmage Emeritus (for Starstorm), Storm-Kiln Artist (for Djinn Illuminatus) and Springleaf Drum (for Bonder's Ornament). The full list has 12 swaps, each scored with synergy, inclusion and lift.

How much does it cost to upgrade Arcane Maelstrom?

All 12 swaps cost about $9.97 at the cheapest paper printings (TCGplayer market prices via Scryfall, 2026-10-28). If you want to spend more, the guide also covers Snap ($3.25) and Veyran, Voice of Duality ($2.22).

What should I cut from Arcane Maelstrom?

The weakest cards for this commander are Channeled Force, Chemister's Insight and Clash of Titans. The guide explains the reason for every cut, and swaps each one for a card that scores higher.

Which cards should I keep in Arcane Maelstrom?

Keep Growth Spiral, Harrow, Wilderness Reclamation, Frantic Search and Twinning Staff. These are the cards doing the deck's heavy lifting.

What does Kalamax do?

Kalamax, the Stormsire costs {1}{G}{U}{R} and is a 4/4 Legendary Elemental Dinosaur. Whenever you cast your first instant spell each turn, if Kalamax is tapped, you copy that spell and may choose new targets for the copy, and whenever you copy an instant spell Kalamax gets a +1/+1 counter. The key phrase is "if Kalamax is tapped," so tapping Kalamax before you cast an instant is what makes the deck work.

More Commander 2020 (Ikoria) upgrade guides

All precon upgrade guides

How the numbers work

Inclusion is the share of Kalamax, the Stormsire decks (8,812 of them when this was written, 2026-10-28) that play the card. Synergy is how much more often they play it than other decks in the same colours. Oracle score is synergy × 0.6 plus inclusion × 0.4, the same blend The Oracle uses to rank cards for a deck. Lift compares how often the card appears in these decks with how often it could, capped at 8× here; it is shown for context and does not change the score.

Two cautions. Players who run the precon unmodified count as Kalamax decks, which flatters every card the precon contains. Lift is high for many instant cards because few decks play them outside an instants deck, so use lift to compare cards, not to judge one in isolation. A card the commander's decks do not usually play counts as 0 in the average score. Prices are the cheapest non-foil paper printing on TCGplayer (via Scryfall), in USD, and move daily.