Ascendant Dustspeaker

In Commander, Ascendant Dustspeaker slots cleanly into Izzet and Grixis spellslinger decks that already want to chain instants and sorceries — the free cast each trigger generates is genuine card advantage at scale, and a 3/4 flier is relevant enough to survive early board pressure. Outside Commander, the six-mana cost is a serious liability: in Modern, Pioneer, and Legacy, the game is often decided before Ascendant Dustspeaker can attack once, and the payoff doesn't justify the tempo loss against faster threats. Pauper is legal on paper but the competition at common is fierce and the mana ask is simply too high for what the format demands. Standard is the one non-Commander venue where it's worth a look in a dedicated spells deck, though even there it's a finisher, not a threat.