Maybe Volatile Rig?

I'd run 4 copies of Reckoner if you are going to run damage through Stuffy Doll. You would get a lot of versatility from Aurelia's Fury.

Maybe Inquisitor's Flail and Illusionist's Bracers for the artifact theme?

Izzet Staticaster? Magmaquake? Pit Fight? Rolling Temblor?

Unfortunately I only have 3 copies of Boros Reckoner, but I'm okay with that. I've considered running 4 Stuffy Doll though.

I like the Aurelia's Fury idea, that could get nasty. I just can't really decide what colors I want to splash. Keep it 2-3 colors, or just go all out 5 color artifact deck? I'm not sure...

I only have 1 Inquisitor's Flail but it does fit this deck nicely. Also, I have 1 Illusionist's Bracers, but I'm not sure it fits in well with the cards I am running.

Just scale back the keyrunes and prisms a tad...you should be able to cut 5 of those artifacts.

Also...it may be worth doing some extra keyrune cutting to add 2-3 extra lands...your CMC average is a tad high to try to run 20 lands consistently with positive effect.

Well, this was supposed to be an artifact deck. The keyrunes provide ramp, the Prophetic Prism provide some mana color fixing (and draw power) and the Chromatic Lantern does both.

This is why I'm running only 20 lands. With the artifacts that can produce mana and 4 Farseek I don't foresee problems as long as I get at least 2-3 lands.

The keyrune artifacts also work as my creatures for blocking/attacking. If anything I think it's the Sorcery cards I need to cut down.

Seems fun, but what's a walker deck with Mammary Adept and no Tamiyo? +1

Good point. Never have actually gotten my hands on a Tamiyo, the Moon Sage though.

It was more Walker heavy until earlier today when I started messing around with alternate win-condition shenanigans and trimming some Planeswalkers. I'm still not sure what to settle on.