Sami, Wildcat Captain

Affinity has almost always lived on artifacts casting artifacts: the Mirrodin-era engine that let a deck of trinkets vomit itself onto the table. Bolting the mechanic to a Boros creature that grants it to every spell you cast rewires the incentive entirely. The cost reduction no longer wants a critical mass of cheap artifacts for their own sake; it wants a board of artifacts and a hand of expensive payoff spells, red burn and white removal and fatties, priced down toward free by the metal already in play. The 4/4 body with double strike and vigilance is the closing argument, not the plan: it attacks for eight, stays back to block, and does not need to connect to matter because the affinity clause is a static ability that works from the moment it resolves. The tension is that the reduction only helps while she is alive and the artifacts stay on the board, so the deck is asking you to protect a six-mana creature and commit to the sweeper-vulnerable permanents that power her at once. Everything about her says spend big and spend often: the artifacts are the ramp, the spells are the payoff, and she is the discount window that makes the whole exchange run in one color pair that rarely gets to cheat on cost this way.