This is the list I used to get to Master's two months in a row.
It's a solid Midrange grind list that seeks to outvalue your opponent due to the fact that it basically never runs out of gas. It's not too expensive to craft given that only two sets of Legendaries must be created (Makto and Sediti), and the rest are from Campaigns. It's also a reliable Gauntlet list that I use in Master's with almost 100% success rate.
The strength of the deck, as I mentioned before, is that it is nearly impossible to run out of gas. It is extremely rare that you ever die because you ran out of cards to play. If you die it will usually be because your opponent raced you down, not because you ran out of options. Obviously, you can still get mana screwed, but the deck has more avenues than most in order to ensure that never happens (such as using Street Urchin to draw a power card from your opponent's deck in an emergency).
Even if your opponent runs graveyard or recursion hate, such as Gavel or Avigraft, the deck has so many threats and win conditions that you can usually brute force your way through it, and punish your opponent for their tempo loss.
It's straightforward, simple and easy to play, works well in Gauntlet, isn't too expensive to craft, and is a lot of fun.
The basic gameplan is to get to 5 mana (bonus if your Ramp on Turn 3 with Icaria), then slam down Makto or Sediti, giving you a long-term value advantage for the rest of the game. As soon as you get into an unfavorable boardstate, you can Harsh Rule (use Vara to remove aegis if necessary) which will typically be backbreaking for your opponent, while you continue to enjoy the endless value of Revenge and Curse of Provocation.
Essentially, there are few decks that can out-grind you in this way, especially as you continue to put pressure on your opponent every turn. This deck works surprisingly well against Aggro. There are plenty of lifesteal options to keep you alive early on, and typically once you Harsh Rule or Pristine Light, they've run out of gas and the game is over.
Stormhalt Knife can save you in a pinch (when it's free), after which you simply lifesteal your way back to a healthy hp total.
Crownwatch Press-Gang is good as a blocker, an Onslaught enabler, and to draw a million Street Urchins which can be used to continuously create value by stealing your opponent's cards, or used as Market fodder.
Cull the Deck and Devour are both good ways to reach your recursion faster, find power in case you get screwed, or to look for Merchants/Harsh Rules in order to salvage an unwinnable board state. FAQS: 1. Only Harsh Rule? Why doesn't this deck run more removal?!
-For a long time I had Desecrate in the list instead of Icaria. The problem is that, for the most part, single-target removal only slows your gameplay down and is largely unnecessary. The goal is to put pressure on your opponent by grinding them down, then clear losing board states with a nuke, after which you gain the undeniable advantage (due to recursion and Curse of Provocation, as well as many strong card draw options).
Having single-target removal in your hand often times does nothing, and doesn't synergize with the Revenge effect that encourages you to make trades on the board (or wipe the slate clean), allowing you to win a long-term war of attrition. You could obviously swap out Cull the Decks or Devour (or Icaria) for some extra removal, but this will greatly hurt your consistency and the amount of pressure you can apply to your opponent. Remember, the purpose of the deck is to keep the pressure up, not to have answers for everything.
2. Why haven't you included any FoX cards?
-If you find something in the new set that improves the list, be my guest!
3. Why don't you have "X" in the market?
-For me, there are 4 cards in the market right now that are irreplaceable in this list. That is:
A. Pristine Light
B. Regent's Tomb
C. Stormhalt Knife
D. Dizo's Office
Pristine Light acts as a poor man's Harsh Rule and can get you out of many sticky situations (by allowing you to play it the same turn you draw it from the Market). Regent's Tomb is a powerful mid-game Site, allowing you to gimp your opponent's removal, Mana fix yourself, and give yourself more recursion. It does absolutely everything you need. Stormhalt Knife can and will save your life against aggressive lists. Dizo's Office is an end-game Site that will seal your opponent's fate with its powerful abilities.
As far as the 5th market option, I'm still not sure what works best here. Right now I have Desecrate in case of the need of single-target removal, but I've never had to use it before. You could substitute Gavel, Burglarize, a power card, a FoX card, or many other things. Like I said, this is a flex spot. The rest I consider sacrosanct.
Here's a video with more details and some gameplay footage. EDIT:
In the end I decided having an extra power card in the Market is useful more often than Desecrate. This deck usually does not have problem with mana screw, but in the few cases you get bad luck, this can save you. Still, this is a flex spot in the market that you can use at your discretion.