Mainboard (60)
Creatures (41)
Sorceries (14)
Artifacts (1)
Mono-Red Madness is a burn-heavy aggro deck that wins by dealing 20 damage quickly through Kessig Flamebreather, Guttersnipe, and direct burn spells before you can assemble your combo. Healer of the Glade provides cheap, recurring life gain that buys critical extra turns against their damage-based game plan, letting you survive long enough to find Balustrade Spy and Dread Return. Vitu-Ghazi Inspector provides an additional body and a clue for card selection. Mesmeric Fiend and Masked Vandal are too slow and their targets are largely irrelevant against a deck that mostly operates at instant speed with few problem permanents. The game plan is simple: race their clock by staying above zero life while assembling the combo as fast as possible.
Grixis Affinity is a fast artifact-based deck that wins through card advantage from Ichor Wellspring and Reckoner's Bargain, then closes with Myr Enforcer and Utrom Monitor. Your primary goal is to assemble the Balustrade Spy combo as quickly as possible before they stabilize with Krark-Clan Shaman, which can repeatedly sacrifice artifacts to wipe your small creatures. Faerie Macabre comes in as a free graveyard-hate creature that can also be pitched to Dread Return, disrupting their Blood Fountain and Nihil Spellbomb recursion while being immune to Galvanic Blast if you're careful. The extra Mesmeric Fiend copies are brought in to strip Nihil Spellbomb or countermagic from their hand before you go off, since a resolved Nihil Spellbomb in response to your combo is one of the few ways they can stop you. Masked Vandal comes out because artifact destruction is less critical when you're racing to combo rather than grind, and their artifacts are primarily utility pieces rather than must-answer threats.
Dimir Terror is a tempo-control deck that wins by filling its graveyard with Thought Scour and Mental Note to power out cheap threats like Tolarian Terror and Gurmag Angler, backed by Counterspell and Snuff Out. Your primary game plan is to combo off as fast as possible before they can establish countermagic, since they have limited interaction in game one. Post-board, they bring in Nihil Spellbomb and potentially Annul to disrupt your combo, so bringing in Faerie Macabre lets you answer their graveyard hate at instant speed without tapping out. The extra copies of Mesmeric Fiend come in to disrupt their hand and strip countermagic before you attempt to go off, which is critical since Counterspell and Spell Pierce are their primary way to stop you mid-combo. Masked Vandal has minimal targets in their maindeck, making it the cleanest cut.