This is a mirror-like matchup against another Gruul ramp deck full of Eldrazi Spawn tokens from Writhing Chrysalis and Malevolent Rumble, plus land destruction via Mwonvuli Acid-Moss and Thermokarst. Breath Weapon deals 2 damage to each non-Dragon creature, cleanly sweeping their 0/1 Eldrazi Spawn tokens and slowing their ramp. Deglamer can strip a Utopia Sprawl or Wild Growth to blunt their mana acceleration in a race where whoever ramps faster usually wins. Rancor is less impactful in a matchup decided by board state and land destruction, so we favor proactive disruption.