Focus Fire

In Commander, Focus Fire earns its slot as efficient spot removal that doubles as a finisher on wounded creatures — spreading counters across three small blockers is a real option, and stacking all three on a single threat handles most utility creatures cleanly. In competitive 1v1 formats like Modern and Pioneer, two mana at instant speed for three damage-equivalent counters is on the fringe of playable but faces stiff competition from cleaner removal like Lightning Bolt; Focus Fire won't displace the format staples but isn't unplayable in lower-power aggro or -1/-1 synergy builds. Pauper is where Focus Fire has the most ceiling outside Commander, since the commons pool makes efficient removal genuinely scarce and -1/-1 counter synergies have real support at that rarity.