If you are mostly capping out at hitting three mana on time, 20 to 22 is the right spot depending on how well you operate off a land or two
More importantly, his attack trigger doubles counters on all Spiders and legendary creatures you control
Since this thing saw print I have seen a lot of games end where people felt very safe and die to 10 direct damage from four mana with this and Fireblast
While it might seem a tall order to have five creatures die, its not that difficult to pull off

Commander 2013: Mind Seize 2026 budget upgrade Report Deck Name Format: Commander User Submitted Deck Deck Date: Jun 5, 2026 Deck Primer / Description removed: Urza's Factory Rupture Spire Opal Palace Grixis Panorama evolving wilds Dimir Guildgate Akoum Refuge Rakdos Guildgate Izzet Guildgate 1 island 1 swamp 2 mountain Price of Knowledge Obelisk of Grixis Armillary Sphere Opportunity Fissure Vent Annihilate Strategic Planning Vision Skeins Starstorm Skyscribing Molten Disaster Dismiss Hooded Horror Terra Ravager Augur of Bolas Grixis Charm Crosis's Charm Vivid Marsh Vivid Creek Thraximundar Added: exotic orchard sulfur falls dragonskull summit drowned catacomb sunken hollow shivan reef smoldering marsh path of ancestry cascade bluffs bloodsoaked insight waterlogged teachings foreboding ruins Hit the Mother Lode worst fears Great Intelligence's Plan mana geyser skull storm Mindsplice Apparatus arcane signet gilded lotus fellwar stone izzet signet dimir signet Resonating Lute Mana Sculpt Tablet of Discovery Wisdom of Ages Fandaniel, Telophoroi Ascian rakdos charm Kavaron, Memorial World Flamekin Village Amonkhet Raceway Kefka, Dancing Mad

Each player also has a discard pile