“Simic Rhythm is a tempo-combo deck that uses mana acceleration from Llanowar Elves and Nature's Rhythm to flood the board with creatures ahead of curve, leveraging Gene Pollinator and Badgermole Cub to generate incremental value off each land drop or spell. The deck builds toward overwhelming threats like Craterhoof Behemoth or a wide token army via Spider Manifestation, using Quantum Riddler and Ouroboroid as resilient mid-game engines that grind out value. Multiversal Passage and the blue splash provide interaction and reach, while the sideboard pivots toward counterspell-backed disruption against control and graveyard hate against attrition matchups.”
Missing sideboard cards? The full 15-card sideboard runs about $124.
Buy sideboard on ManapoolMono-Green Landfall has almost no interaction (no removal spells in their mainboard list) so our two copies of Spell Pierce are dead weight and come out. Extra Surrak, Elusive Hunter gives us more uncounterable, trampling bodies to race their board-building plan and punishes any attempt they make to target our creatures. Heritage Reclamation lets us blow up Earthbender Ascension or Ba Sing Se-adjacent value engines like Esper Origins before they compound, since this is a grindy mirror-style matchup where extra card advantage denial matters. Terrian, World Tyrant is a clunkier top-end that doesn't do much their creatures can't already out-body, so it steps aside for more proactive, protected threats.
Dimir Midrange leans on The Wondrous Wasp, Enduring Curiosity, and Requiting Hex-style removal to grind through our threats, so Defend the Rider keeps our best creature alive through their removal package and lets us push damage. Soul-Guide Lantern disrupts Enduring Curiosity's return-from-graveyard value and denies any incidental graveyard synergy while giving us a way to draw a card later. Spell Pierce underperforms since this deck curves out with efficient creatures and has plenty of mana to pay around it by the time key spells resolve, so it and the top-heavy Terrian, World Tyrant plus a Lumbering Worldwagon step out for more resilient threats.
Dimir Excruciator is a discard-and-removal deck (Duress, Deceit, Bitter Triumph, Requiting Hex) that wants to strip our hand and pick off threats one at a time, so Defend the Rider's hexproof/indestructible mode protects our best threat from their removal suite. Soul-Guide Lantern exiles a card from their graveyard on entry, disrupting their Bitter Triumph discard synergy and denying recursion value, while its sacrifice ability can wipe their whole yard if needed. Spell Pierce is weak here since they have plenty of mana by the time they cast their key spells and the deck isn't spell-dense early. Terrian, World Tyrant and one Lumbering Worldwagon come out as they're slow against a deck full of efficient one-for-one removal that trades up easily into our bigger threats.