Response // Resurgence

The split structure tells you exactly who this card is for: the aggressive Boros player who wants a slot that never rots in hand. Response is the cheap insurance half, a hybrid-cost instant that punishes a block or an attack with five damage, enough to clear nearly anything standing between your team and the red zone. Resurgence is the haymaker, an extra combat phase wrapped in first strike and vigilance so a full board can commit without leaving you tapped out and exposed. The phase math is the reason the closer earns its cost: cast in your precombat main phase, Resurgence spins up an additional combat, then an additional main phase, then hands you back the turn's normal combat, so the added main sits between two attack steps as a window to reload, replay, and rearm the swingers before the second wave. Extra combat has long been red-and-white territory, the Relentless Assault and Aggravated Assault tradition, but those cards ask for a payoff already deployed and a body left upright to swing again. Folding the effect onto a Boros split card hands white-red both the defensive answer it might want early and the finisher it wants late, in one card. The hybrid mana on Response is the quiet discipline that makes the whole thing castable: the removal stays live in a mono-red or mono-white shell while the full two-color price is reserved for the explosive back half.