Post-Theros RDW, with a splash of white for some excellent removal and access to cool Boros spells. If you can pull it off, Legion's Initiative plus Purphoros' effect of pinging for 2 will destroy an opponent by blinking your creatures up and down.
Creatures are pretty standard post-rotation Red Aggro stuff, with the exception of Firemane Avenger. Having Searing Spear whenever you attack en masse will thin blockers or just punch harder. With Legion's Initiative down, he's a 4/4 also.
Note: Wojek Halberdiers is actually the newly spoiled Akroan Hoplite (WR, 1/2, gains +1/+0 for each attacking creature.).
Enchantments feature our friendly red God, who could very well spend some time swinging away, but his effect and field-wide attack buff are more than enough. Chained to the Rocks is there for excellent, cheap spot removal. Don't forget you can pair this with your Sacred Foundries. Finally, the most controversial part of the deck, Legion's Initiative. By flickering your creatures, you can dodge board wipes, and reactivate several effects. With half of Theros left to spoil, I will keep an eye out for additional creatures with Enter the Battlefield effects. In addition, it adds a little extra punch to my offence, and makes Ash Zealots into rather formidable blockers, and my Reckoners into holy terrors.
At Instant speed, the exceptional Boros Charm further protects my dudes, while Magma Jet and Warleader's Helix provide burn and excellent utility to boot.
The balance of the land will have to tweaked, as I'm not sure I like the slower pace of the Theros dual lands, but the scry is pretty awesome. Everything but them and the Plains can be used with Chained to the Rocks, so that's pretty cool.