This deck is a dirty monster. I haven't tested it yet but it goldfishes like a champ.
The deck is all-in mana denial boasting 28 main deck mana denial slots. There is zero removal. We're depending on not allowing the opponent to cast spells by aggressively dropping mana-denial-dorks and closing out the game fast with quick heavy beats.
The key is to take advantage of Root Maze by not running fetchlands ourselves all the while punishing opponents who do. This strategy seemingly should be good in a UR Delver meta.
If we don't get a first-turn Root Maze we have Elvish Spirit Guide which can power out a turn one Leonin Arbiter and/or Thalia, Guardian of Thraben. Both of which as you probably already know are insane with Root Maze. ESG also helps us power through our own Root Maze by allowing us to cast Root Maze and a mana-dork on turn one.
With mana-dorks, we can easily establish a turn two Trinisphere, Thalia, Heretic Cathar, Sanctum Prelate, and/or Anointed Peacekeeper. Turns three, four, and/or five we have the nails in the coffin with Armageddon.
Steel Leaf Champion is probably the flex slot however his usual drawback of ggg is not a drawback here and he can close out games fast with the backup of a little mana denial. As far as big beat-sticks go I think he is the best option by far. Tarmogoyf in theory shouldn't get too big if our deck is working correctly. My thoughts are to run SLC in the main-deck and side him out based on game-one information.
There are a bunch of other synergies that pop up such as Anointed Peacekeeper giving you information for Sanctum Prelate, Noble Hierarch buffing dudes, Peacekeeper's vigilance, SLC's evasion, ESG is an extra body late game, etc..
Everything synergizes very well together and there isn't much in the way of nombos.
I'm thinking that the sideboard should be running some form of removal in the vein of Skyclave Apparition, Karakas, Cathar Commando and STP.
Other cards come to mind such as Winter Orb and Suppression Field but I'm not that impressed versus cards that do similar things but also have legs and a body to close out the game.
Here's the deck:
Root Maze Parfait:
Beatz / Denial: 23
4x Steel Leaf Champion
4x Anointed Peacekeeper
4x Leonin Arbiter
4x Sanctum Prelate
4x Thalia, Guardian of Thraben
3x Thalia, Heretic Cathar
More Mana Denial:
4x Root Maze
3x Trinisphere
2x Armageddon
Ramp: 12
4x Noble Hierarch
4x Birds of Paradise
4x Elvish Spirit Guide
Land:
4x Savannah
4x Brushland
4x Razorverge Thicket
4x Temple Garden
Sideboard:
???
EDIT: Thalia, Guardian of Thraben is really really good when almost every card in the deck is a creature.

