“Izzet Spellementals is a tempo-combo deck that leverages spell-triggered synergies to grow its elemental creatures (primarily Hearth Elemental and Eddymurk Crab) while filtering through the deck with cantrips like Opt and Sleight of Hand. The deck uses a suite of cheap interaction and card selection to protect its threats and chain spells together, with payoffs like Sunderflock and Colorstorm Stallion closing out games once the engine is running. The core gameplan is to establish a threat early, then use each subsequent spell to both advance board state and trigger incremental advantages, overwhelming opponents who cannot answer multiple growing threats simultaneously. Cost reduction only changes what they pay: on the battlefield Hearth Elemental is still mana value 6, Eddymurk Crab 7 and Sunderflock 9, so answers limited to mana value 2 or less (Seam Rip, Witherbloom Charm's destroy mode, Requiting Hex) cannot touch their threats; their only small nonland permanent is usually Ghost Vacuum.”
Missing sideboard cards? The full 15-card sideboard runs about $21.03.
Buy sideboard on ManapoolMono Green Landfall floods the board with small creatures (Llanowar Elves, Sazh's Chocobo, Keen-Eyed Curator) and ramps hard, so Slagstorm's 3 damage to each creature mode sweeps their early plays while leaving our Hearth Elemental and Eddymurk Crab untouched. Spell Snare is weak here since most of their key threats (Mossborn Hydra, Icetill Explorer, Earthbender Ascension) sit above mana value 2. Disdainful Stroke only hits mana value 4 or greater, so it is for Icetill Explorer, Mightform Harmonizer, and Sapling Nursery; Mossborn Hydra and Earthbender Ascension are mana value 3 and slip past it. Keep the core engine intact and lean on card selection to find Slagstorm and our big threats.
Dimir Midrange's Requiting Hex only hits creatures with mana value 2 or less, so Hearth Elemental and Eddymurk Crab dodge it entirely; their real threats to us are Kaito, Bane of Nightmares and card advantage engines like Enduring Curiosity. Spell Pierce taxes their removal and countermagic while they're tapped out early, and Flashfreeze is irrelevant here since Dimir casts no red or green spells, so hold it back unless they bring in red. Impractical Joke is a weak removal spell against their larger bodies, so it comes out for extra protection. Keep Spell Snare in since they run Watery Grave fetches and cheap interaction at mana value 2.
BRG goes wide with cheap creatures like Gene Pollinator, Greedy Freebooter, and Biotech Specialist, making Slagstorm's 3 damage to each creature a strong sweeper that leaves our bigger threats alive. Disdainful Stroke can counter their expensive plays like Smaug the Magnificent, Wolverine, Fierce Fighter, or Rottenmouth Viper, though their cheap removal (Requiting Hex, Witherbloom Charm) can't touch Hearth Elemental or Eddymurk Crab anyway. Spell Snare is trimmed since it only counters spells with mana value exactly 2, so it misses Requiting Hex (mana value 1) and their one-drops, though it still catches cards like Witherbloom Charm and The Sackville-Bagginses. Keep Burst Lightning in low numbers since it still answers Gene Pollinator and Callous Inspector cheaply.