Couch312

Chromatic Lantern. It's almost a necessary card in a four color deck.

Why aren't you running 4 ravagers and 4 cranial plating?

Spell Pierce would be a great sideboard card. Cranial Plating would be good card as well with all your artifacts. I would also run mox opals and since Erayo is legendary, maybe one or two less of her for more Canonists?

Etherium Sculptor over Trinket mage? Broodstar over Qumlox? Shield Sphere over Darksteel Relic? More artifact lands over the basic and buddy land?
If you're going for budget but it isn't a huge issue, Cranial Plating($2) over Hunger of Nim?

I'd replace Centaur Healer for 2 Trostani and 2 Karametra. If you found a spot for Courser of Kruphix it would partner with karametra, allowing you to cast creatures for life with trostani, then search for a land and drop it for more life with Courser in play... at least that's the combo I'm running.
Maybe replace the armada worm for courser?

In my opinion, I would replace the Call of the Conclave with Selesnya Charms. I would also replace the phalanx leader with hero of iroas and replace ephara's enlightenment with eidolon of countless battles. Ranger's Guile would make a better sideboard card over gainsay. And then you could mainboard a few turn one cards, maybe experiment one or elvish mystic? Just some thoughts.

Heliod for Vigilance. With is relevent with any weenie type deck. Celestial Flare over Glimpse of the Sun God. I would personally choose ethereal armor over Gods Willing.
You could also think about Reap what is Sown or Common Bond.

Well, I meant Kaalia as the commander, since she can pull any demon you want from your deck.

Flying? Cavalry Pegasus makes all humans fly.

I was gonna say, elvish piper, most broken green card ever.

If you wouldn't mind, I decided to post my Gruul deck on here for critique. Would you be so kind? Or unkind, either or, as long as it results in a better deck.:D
http://www.mtgvault.com/couch312/decks/gruul-aggro/

Alright, as long as you have a reason.:P

Is there a reason Ghor-Clan Rampager is not in here? It's under a dollar and is amazing.

I would find spots for any of the following, Boros Elite, Daring Skyjek, Cavalry Pegasus. I would take out boulderfall, ordeal of purphoros, chosen by heliod, Akroan Conscripter, Akroan Phalanx, Labyrinth Champion, and Bomber Corps. If you still have spots to fill afterwards, ordeal of heliod over ordeal of purphoros.
Oh, and I would take out the nyxborn shieldmate and hold at bay for more target spells, like another coordinated assault, a few more titan's strength and boros charms.
Other cards that are useful, Brave the Elements, and Fortify. Both work well with battalion.
If you're going for budget, the only thing over a dollar in that list is boros charm, everything else is maybe a quarter.
Now for non-budget.
Frontline Medic is also amazing, and good for slowing down sphinx's revelation. Spirit of the Labyrinth would be a good sideboard. Heliod, to give everyone vigilance, spear of heliod, to make everyone bigger. Tajic, Blade of the Legion is indestructible and his battalion is beastly.

Why not Kaalia the Vast and Master of Cruelties?

Clearly, need mox opals.:P
Actually, I could use some help on one of my decks, if you would be so kind.
http://www.mtgvault.com/couch312/decks/artifact-affinity-legacy/

You might be able to replace Howling Mine for Springleaf Drum as well and maybe find a spot for some 0 cost defenders.

You could easily drop the Great Furnice and one Ancient Den for four tombs.

Thought about Ancient Tomb? Tap for two colorless for two life.

Gyre Sage over Voyaging Satyr. Kalonian Hydra over Mistcutter, maybe drop a Zhur-Taa Druid for a Domri Rade. Just my thoughts.