I have posted just days ago regarding the updated build of Mono Red decks in versions of speed aggro or Devotion and it looks they will be getting a huge upgrade in Dragons of Tarkir. First reason is the printing of this card, Dragon Whisperer.

While this card is more suited to a Red Devotion build, it also deserves a slot in an aggro build. Its Flying activation and late game mana dump on the pump ability makes it an efficient creature for the deck. Its Formidable activation though is more possible for the Red Devo because of four-powered critters in the form of Ashcloud Phoenix, Fanatic of Mogis and Stormbreath Dragon.

Here is a possible deck list of Red Devotion in post Dragons of Tarkir Standard:

Creatures
2 Ashcloud Phoenix
3 Dragon Whisperer
2 Eidolon of the Great Revel
3 Fanatic of Mogis
4 Flamewake Phoenix
4 Firedrinker Satyr
4 Goblin Rabblemaster
4 Stormbreath Dragon
2 Thunderbreak Regent
3 Zurgo Bellstriker

Spells
4 Crater’s Claws

Lands
2 Nykthos, Shrine to Nyx
21 Mountain
2 Wooded Foothills