Been playing with a few different decks that try and abuse Purphoros, Bronze-Blooded. I didn't like the Izzet build as you can't really do anything early game besides drawing cards and just die to aggressive decks. Ended up looking to Boros to help with early game interaction. Currently running this build, which has been fun to play and does win some games. Certainly not a top tier high win rate deck, so don't waste your wild cards on this deck expecting that.

Creatures

Purphoros, Bronze-Blooded: Pretty much the main engine for this style of deck. Originally had 4, but multiples are really bad due to Legendary status.

Ilharg, the Raze-Boar: Nice back up plan and is hard to permanently remove. Pairs very nicely with Terror of Mount Velus, repeatable double strike is great! Ilharg's attack ability will not trigger Drakuseth's attack ability, so keep that in mind.

Cavalier of Flame: Allows for your most busted turn 5 plays. With Fire of Invention in play, you can drop both Cavalier and Purphorus on turn 5. Purphorus's activated ability will put another creature in play and Cavalier's activated ability will give everyone haste and a pump. Just make sure you plan out your lands drops to have 5 untapped lands.

Drakuseth, Maw of Flames: Another great creature to help turn on devotion. Comes in handy as another board wipe to buy turns.

Terror of Mount Velus: Been really impressed with this creature. Just ends games. Really wish he had triple red to help devotion.

Support

Idyllic Tutor: Another great reason to go Boros for this style of deck. Started off with only 2, but quickly bumped to a full playset. Being able to tutor for combo pieces or other support enchantments is fantastic.

Fires of Invention: Not much commentary needed here. Card supports your biggest turns and "fixes" your mana. Had 4 but went down to 2 when I added tutors. Kept 2 incase first gets removed or if you really need another red source for devotion.

The Birth of Meletis: Just a fantastic card for this deck. Helps you hit land drops, provides an early blocker and gains life.

Deafening Clarion: Another strong Boros card. Early game sweeper and the lifegain side could provide some value.

Shatter the Sky: Main board sweeper and is an ideal turn 4 play with Fires of Invention against creature decks.

Banishing Light: Catch all removal for annoying creatures, planeswalkers and enchantments.

Omen of the Forge: May seem like a weird inclusion, but can kill an early creature and then stick around to add devotion. Late game scry is relevant too.

The Akroan War: Running as a silver bullet that can be tutored when the need arises. Ideally used to push through damage by stealing their best blocker.