Nahiri, Storm of Stone

In Commander, Nahiri, Storm of Stone slots cleanly into Equipment-matters builds — Nahiri, the Lithomancer decks are the obvious home, but any Boros or Mardu Equipment commander benefits from the free equip trigger on opponents' turns, which turns combat tricks into genuine tempo plays. In Modern and Pioneer, the static first-strike grant is relevant in aggressive Equipment shells, though three mana for a planeswalker with no immediate board impact is a hard sell in those formats where the game is often decided by turn four. Legacy and Vintage have access to better options at this cost, so Nahiri, Storm of Stone sees essentially no play there. Oathbreaker is where the card gets genuinely interesting — as the oathbreaker herself, the free equip ability on opponents' turns is always live and she enables aggressive Equipment strategies at a lower power ceiling.