Missing sideboard cards? The full 15-card sideboard runs about $44.87.
Buy sideboard on ManapoolMono Red Madness wins by racing with burn and madness triggers, so lifegain and incidental toughness buy crucial extra turns. Healer of the Glade's 3 life on entry directly offsets Voldaren Epicure, Lightning Bolt, and Fiery Temper damage, while Vitu-Ghazi Inspector's reach and potential +1/+1 counter plus 2 life help stabilize the board. Mesmeric Fiend is weak here since it only strips one card and the deck has redundant burn, and Quirion Ranger's tempo isn't worth it in a race. Keep the full engine (Lead the Stampede, Winding Way, Generous Ent, Sagu Wildling) intact since you need to assemble your graveyard-fueled board as fast as possible.
Dimir Control leans on counterspells (Counterspell, Spellstutter Sprite) and removal (Snuff Out, Cast Down) rather than graveyard synergies, but Faerie Macabre still gives you a flying blocker against their Spellstutter Sprites and Faerie Seers while providing a relevant discard-exile option against Gurmag Angler's delve if needed. Masked Vandal can answer Bojuka Bog-adjacent concerns or any artifact/enchantment threat they bring from the board. Mesmeric Fiend's one-time Thoughtseize effect is less impactful against a deck full of card draw and redundant answers, and Tinder Wall is replaceable since this matchup is more about grinding through countermagic than ramping quickly. Focus on resolving multiple threats per turn to beat their one-for-one interaction.
Affinity floods the board with artifact lands and artifact creatures like Refurbished Familiar and Utrom Monitor, so extra artifact removal is valuable. Masked Vandal can exile a creature card from your graveyard to remove a key artifact or enchantment such as Cryogen Relic or a Bridge land, and Undergrowth Leopard gives you another cheap way to destroy a target artifact or enchantment. Tinder Wall and Elves of Deep Shadow are the least impactful mana creatures here since Affinity races quickly and you'd rather have proactive answers than marginal ramp. Keep your core graveyard and creature-flood plan intact since Affinity has limited ways to stop it.