This Gruul deck is a mana-value-cheating value/ramp engine built around Ancient Stirrings, Malevolent Rumble, Urza's Saga, and Eldrazi Temple producing free or cheap value; Consign to Memory counters their colorless spells and key triggered abilities, while Damping Sphere caps the extra mana their Eldrazi Temple generates and taxes multi-spell turns. Spell Pierce is weak since most of their key plays (Ancient Stirrings, Kozilek's Command) are resilient to a tax they can easily pay around with their ramp. Otherworldly Gaze is too passive against a deck assembling a fast Broodscale/Devourer of Destiny clock. Keep Thoughtseize and Fatal Push in as they strip or answer their key threats and payoffs before they resolve.

Gruul Basking Broodscale Combo runs Urza's Saga to make Construct tokens and relies on lands like Eldrazi Temple and Ugin's Labyrinth for ramp, so Meltdown can wipe out their Urza's Saga-generated Constructs and other cheap artifacts like Vexing Bauble and Soul-Guide Lantern for a scalable blowout. Damping Sphere caps the extra colorless mana their Eldrazi Temple and Ugin's Labyrinth produce and taxes them when chaining cheap spells like Ancient Stirrings and Malevolent Rumble in a turn, slowing their assembly of Devourer of Destiny or Emrakul. Spell Pierce and Otherworldly Gaze are too passive against their proactive ramp-into-big-threats plan. Keep Fatal Push and our discard spells to strip key pieces or kill small creatures like Glaring Fleshraker before they scale up.

Gruul Broodscale leans hard on colorless-heavy lands like Eldrazi Temple and Ugin's Labyrinth plus colorless Eldrazi threats, so Damping Sphere slows their explosive mana from multi-mana lands and caps big multi-mana turns. Meltdown for X=1 sweeps their Blade of the Bloodchief, Springleaf Drum, and any Urza's Saga Constructs, while Harvester of Misery's -2/-2 ETB clears their early creatures. Spell Pierce is poor since their key spells (Malevolent Rumble, Ancient Stirrings, Kozilek's Command) aren't easily taxed off {2}, and Otherworldly Gaze/Prismari Charm are too passive against a proactive ramp-into-fatties plan. Keep Thoughtseize and Fatal Push to strip key threats or kill early creatures, using Thoughtseize to discard Devourer of Destiny from hand before it can be cast, preventing its cast trigger from exiling your colored permanents.