Nahiri, the Harbinger

The dirtiest tutor-and-cheat package in two colors that historically wanted nothing to do with it. Boros has always been the aggro corner: burn, white weenies, no library-tutoring engine to speak of. This planeswalker smuggled a Sneak Attack effect into those colors, and the −8 is the whole reason the card built a deck around it. Search up any artifact or creature, put it onto the battlefield with haste, and the line that famously came together was fetching Emrakul, the Aeons Torn or Emrakul, the Promised End for a single hasty alpha strike, the return-to-hand clause irrelevant when the game is already over. What makes the ultimate reachable is that the +2 is loyalty and card filtering at once: it climbs while it loots, turning the discards the deck wanted into incidental value. The −2 is the patience tax that keeps the plan alive, exiling an enchantment outright or any tapped artifact or creature, which lets the card double as removal for the threats that would otherwise race it. The result is a planeswalker that defends itself, advances itself, and ends games through a single button, anchoring an archetype (Jeskai or Mardu control built to ramp to a cheated finisher) that no Boros card had any business enabling.