Infinite combo mill-and-kill deck with Duskmantle Guildmage + Mindcrank
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Fetch components with Dimir Infiltrator or Shred Memory.
Eliminate, counter, or absorb threats with Thoughtseize, Mana Leak, Spellskite, etc...
Use Aether Vial as soon as you can. At two counters, it can really get things moving, pumping out any of your creatures.
Once the loop is set with Mindcrank and Duskmantle Guildmage's ability, it can be triggered without mana via Gut Shot or Dimir Infiltrator attack.
If you don't have these options, but have any mana/land after Duskmantle Guildmage's ability, the loop can be triggered with Thoughtseize, Ghost Quarter, etc...
Don't be afraid to spend life. Use of Polluted Delta, Watery Grave, Thoughtseize, and Gut Shot will require you to spend life as an alternate power source to mana. This is worth it, and is the key to ending the game early. Besides, you aim to end the game between turns 3 and 5 anyway, and you shouldn't have to worry about your life too much that early on.
Even during an opponent's turn, activating Duskmantle Guildmage's ability on a sorcery, instant, or any card that causes them to send or pass a card to the graveyard will trigger the loop as well (As long as it isn't taking your Mindcrank off the battlefield). Deck wins BY turn 5 very reliably, and often before that.
