First off, I would like to say that, while I welcome all criticism and suggestions, I am trying to make this combo more than a casual thing. I think it is fast enough to be Modern viable. We are not shooting for tier 1, but I do not think 1.5 is out of reach. Please keep that in mind when making suggestions.
This deck is based on the Mindcrank/ Bloodchief Ascension combo, but does not require three counters on BCA, since the card is not in the deck, and is instead replaced by Duskmantle Guildmage. This allows us to do a couple things: 1, it allows us to play better cards. The BCA version plays cards like Hideous End and other things that deal a bit of damage in addition to their ability (kill a non-black creature, in HE's case). We get to trim those for Doom Blade and Geth's Verdict to give us some range. Countersquall is a holdover from the BCA list, because I like the card. It could very easily be worse than Mana Leak, and may be replaced in the long run. I also ran Geralf's Messenger in the BCA list, and that is a powerful card, but a bad topdeck lategame. we lose him for Architects of Will, who, at their worst, become another card.
The Big thing we gain from not running Bloodchief Ascension is the ability to Transmute for our entire combo. both Mindcrank and Guildmage cost 2, so we have 11 tutors for them, that also fill other roles in the deck. Dimir Infiltrator can be a decent blocker, and a way to pressure planeswalkers, if needed. Muddle the Mixture is a counterspell, advancing out control strategy, and Shred Memory can be a blowout against Snapcaster Mage, Tarmogoyf, and other graveyard decks, all with the threat of just getting our combo.
Overall, I think the Guildmage build is simply more resilient than the Ascension build, as we just get to be a board control deck until we have 5-6 mana, then we have a combo that is difficult to interact with as a win condition.
Sequencing is VERY important with this deck. You cannot just run out a naked guildmage on turn 2, as he is just a grizzly bear at that time, and will just die. Mindcrank, however, is probably safe to drop on 2.
The goal is to get to 5 lands with a Mindcrank on the board and a guildmage in hand.
Once we get to this point, we play mage, with enough mana up to activate his first ability. this way, if they try to kill him in our endstep, we can activate it, and when their spell goes to the yard, they start the infinite chain, and lose, unless they can destroy the Crank.
If they do not kill him on our turn, anything they do can become a way for us to win. if they attack with a creature that Mage can kill, they die, if they play an instant or sorcery, they die. about the only thing they can do is play permanents, which is fine, because we are a control deck, it shouldnt really advance their board too much.