This is a damage race against a deck full of burn, so keep the mainboard plan intact and just add efficiency. Cast into the Fire deals only 1 damage to each of up to two targets, so it won't kill Kessig Flamebreather (1/3) or Guttersnipe (2/2). What it does well is pick off X/1 creatures like Voldaren Epicure and Sneaky Snacker, ideally two at once, and its exile mode can remove a Blood token. Sneaky Snacker can come back from the graveyard on a third draw in a turn, so don't count on killing it as a permanent answer. Relic of Progenitus is graveyard disruption: its exile-all mode takes away Faithless Looting and Lava Dart flashback and also strips Sneaky Snacker out of the graveyard, so save it for a turn when those matter. Keep Pyroblast in the sideboard; the opponent's only blue card, Sneaky Snacker, is never actually cast. Trim Gingerbrute and Wrenn's Resolve slightly since this matchup rewards damage output over card selection.