This is a pure combo race where their primary threat is assembling Basking Broodscale plus Blade of the Bloodchief to generate infinite triggers for Glaring Fleshraker or Walking Ballista. Consign to Memory is the most important card in the sideboard here, as it counters Urza's Saga's Chapter III triggered ability (stopping them from tutoring Blade of the Bloodchief), Walking Ballista's activated ability mid-chain, and Glaring Fleshraker's drain triggers once the loop begins. Engineered Explosives on 1 answers Blade of the Bloodchief cleanly before they can establish the engine. Stern Scolding and Spell Snare come out because Cavern of Souls naming Eldrazi makes creature counterspells unreliable against their key threats, and Into the Flood Maw's 4-mana cost is too slow when you need to be sculpting your hand and threatening Goblin Charbelcher. Flusterstorm replaces the cut counterspells as cheap, stack-efficient interaction against their noncreature setup spells like Ancient Stirrings and Malevolent Rumble.