Missing sideboard cards? The full 15-card sideboard runs about $72.13.
Buy sideboard on ManapoolThraben Charm's damage mode scales with my board and kills Kessig Flamebreather, Guttersnipe, or Voldaren Epicure before they generate value, and can also exile the opponent's graveyard to strip flashback fuel from Faithless Looting and Lava Dart (note it does nothing against madness-cast Fiery Temper, which is exiled not discarded to the yard). Standard Bearer forces their burn spells like Lightning Bolt and Fiery Temper to target it instead of my face or real threats, buying crucial tempo. Winding Way and some card selection come out since this matchup is a race where cheap interaction and a low curve matter more than incremental card advantage.
Ultimate Alliance scales with my wide board and is an efficient one-mana answer to Tolarian Terror, Cryptic Serpent, or Delver of Secrets once it transforms, dodging their Counterspell/Dispel by being cheap and castable at instant speed after they tap out. Standard Bearer soaks up their removal-lite disruption and protects real threats. Salt Road Packbeast is too slow and clunky against a deck that wants to counter my best spell, so it comes out along with some card selection in favor of a leaner, more resilient curve.
Dust to Dust exiles two artifacts at once, which is crucial against Tron since their Bridges and Giant's Boulder/Expedition Map/Bonder's Ornament are the ramp pieces enabling their big spells, and exile also gets around any recursion. Standard Bearer can soak up removal from Giant's Boulder's late-game ability. Winding Way is too slow against a deck that wants to durdle into a huge mana advantage, so speed and disruption take priority; race them before Tron assembles.