Mainboard (60)
Creatures (23)
Instants (10)
Artifacts (19)
Lands (8)
Mono-Red Madness uses Faithless Looting and Voldaren Epicure to fuel free Fiery Tempers and Sneaky Snackers while Guttersnipe and Kessig Flamebreather compound burn damage on every spell cast. Duress comes in to strip Faithless Looting before it can set up the madness chain or take a Fireblast out of hand before they can close the game. Arms of Hadar is a one-sided reset at favorable moments — their entire creature base (Epicure, Flamebreather, Guttersnipe, Sneaky Snacker) dies to -3/-3, so hold it for when you can clear their board without losing critical attackers of your own. Thorn of the Black Rose comes out because handing Monarch to a burn deck is dangerous, and Jolted Awake and Virus Beetle are too slow or too low-impact when the opponent's discard is intentional madness fuel rather than a real cost. Focus on racing with Refurbished Familiar and Lembas to gain life and stay out of Fireblast range.
Grixis Affinity is a fast artifact-based deck that wins by flooding the board with cheap artifacts, drawing cards through Ichor Wellspring and Thoughtcast, and closing with Myr Enforcer or Galvanic Blast to the face. Dust to Dust is your most impactful answer, efficiently destroying two artifacts at once and disrupting their mana base by hitting their artifact lands. Relic of Progenitus hoses Blood Fountain and any graveyard recursion while providing a free cantrip if they don't have a relevant graveyard. Jolted Awake and Virus Beetle are cut as the discard plan is too slow against their redundant card draw engine, and Thorn of the Black Rose offers little here since board presence and speed matter more than card advantage. Your bounce engine with Glint Hawk and Kor Skyfisher remains strong, letting you replay Refurbished Familiar for life gain and keep pressure up while their Krark-Clan Shaman can punish your small creatures, so prioritize deploying threats with toughness above 1 when possible.
Dimir Terror wins by filling its graveyard cheaply to fuel Tolarian Terror and Gurmag Angler, so Relic of Progenitus is your highest-impact sideboard card — activate it proactively to tax their delve rather than waiting for the perfect moment. Duress comes in to strip Counterspell and Spell Pierce before you commit to a threat, as resolving even one Glint Hawk or Kor Skyfisher through countermagic can be backbreaking for them. Virus Beetle and two copies of Hopeless Nightmare come out because making the opponent discard actively aids their graveyard plan, turning a normally useful effect into a liability. Thorn of the Black Rose is too risky here since Sneaky Snacker, Murmuring Mystic tokens, and flying Tolarian Terrors all threaten to steal the monarch back immediately. Focus on a low-to-the-ground aggressive curve backed by discard and graveyard disruption, as their removal suite of Cast Down and Snuff Out struggles against artifact creatures like Refurbished Familiar that don't die to Snuff Out.