I used to run Elemental Mastery in the deck, and it was amazing when it landed on a high power creature. In my current build though it might not have enough of a payoff, as most of the dudes on my side will be 1/1's or 2/2's.

War Elemental sounds like a great idea. Sure it paints a target on your head, but you already have a target on your head from playing Purphoros. I'm going to add that, the only downside is that it has the potential to turn Purphoros into a creature, which only makes him easier to remove.

The deck looks pretty cool. But if there is one card you could run, it would be Hellion Eruption. Sure, you have Descent of the Dragons in there, but running both wouldn't hurt, imo.

I actually used to run Hellion Eruption in the deck, then replaced it with Descent of the Dragons. It was nice because the majority of the time I don't have enough devotion for Purphoros, God of the Forge to be a creature, so it's just value on my end.

Right now I'm trying to lower the average cmc of the deck to make it faster, but Hellion Eruption can still act as a good finisher. I'd be hard pressed to find space for it though.

Does Fanatic of Mogis end up doing work for you, given that you're trying to keep your devotion down? On the same lines, is Nykthos, Shrine to Nyx actually blowing up for that much?

Most of the time Fanatic of Mogis doesn't deal too much damage off the trigger, but it's still worth it in my mind. Worst case scenario it's 4 damage to each opponent for 4 mana, which isn't too bad. Nykthos, Shrine to Nyx however isn't as good. It can help sometimes, but I wonder if basic Mountain would be better.

What about Skittering Invasion, Rapacious One, or Akroan Horse?

Also creatures that have a low dash cost and don't have to attack every turn are also a good option.

I've actually ran all those cards in previous editions of this deck. They work great, I just prefer to have a lower curve with the deck right now.

Dash is an option I haven't explored, but I'll consider it. Generally this deck doesn't attack much.

Just a heads, but it looks like Zealous Conscripts is missing from your actual deck list.

Thanks for the heads up. I recently had to use it to finalize a trade, and have yet to grab a replacement for it.

Heads up, Kaladesh is bringing Purphoros a new toy: Panharmonicon allows Purphoros to trigger twice per creature entering the battlefield.

Thanks for the heads up dude. I already had my I on Pia Nalaar and Chandra, Torch of Defiance for the deck as well.

Seems like the concept here is firing out as many creatures as possible. I like your base here, but what about these:

Young Pyromancer

Goblin Offensive

Firecat Blitz

Kari Zev, Skyship Raider

Dragonmaster Outcast

Great suggestions! I've actually tried most of those in the deck, and considered those that I haven't tried. I find Young Pyromancer would be better if I played more than 13 instants and sorceries. Goblin Offensive and Firecat Blitz are only efficient token producers at really high mana costs, and I'd rather be casting spells for less than 5 mana. Acutally just go a Kari Zev, Skyship Raider yesterday and added it! I've considered Dragonmaster Outcast, but figure that the pay off is too slow to merit a slot in the deck.