As has been said, I've sorta come to the conclusion that if the locks work, almost any creatures can close it out.

To that end, I've been playing around with Prophetic Flamespeaker, Academy Raider and Goblin Rabblemaster as my creatures. The first two let me dig for cards, which this deck needs desperately, and the Rabblemaster can end the game very quickly all by himself. Further, they all cost 3 mana, they all rock with Umezawa's Jitte, and they can all easily play under Ensnaring Bridge, which I've been maindecking.

I've also been playing around with Chaos Warp. It gets rid of almost anything at instant speed, and the opponent has good odds of wiffing if playing any deck with lots of cantrips/ counterspells/ disruption (combo, Delver, control). It's also occasionally worthwhile to play on my own lands in the late game, as I have almost all permanents.

4x Chalice of the Void
4x Trinisphere
4x Magus of the Moon
3x Blood Moon
3x Ensnaring Bridge

4x Prophetic Flamespeaker
4x Goblin Rabblemaster
2x Academy Raider

3x Umezawa's Jitte

4x Chrome Mox
4x Simian Spirit Guide

4x Ancient Tomb
4x City of Traitors
11x Mountain
2x Cavern of Souls

Sideboard:

4x Chaos Warp
1x Blood Moon
1x Ensnaring Bridge
3x Goblin Sharpshooter
2x Koth of the Hammer
4x Shrine of Burning Rage

http://playtest.tappedout.net/28-07-14-red-stompy/