Dragons - the win conditions, matches particularly well with Foul-Tongue Invocation and Draconic Roar, obviously. 10 is enough to ensure that you almost always have one for the bonus effect.

Bile Blight - Only 2 because double black is not particularly easy to achieve. Strong against all aggro decks, particularly tokens. Some game against accelerators. Weak against traditional control.

Crackling Doom - Maybe the best card in standard and the reason to play these colors. Destroys heroics, strong against midrange and even control. Additional play with soulfire grandmaster.

Draconic Roar - If playing dragons, a simple improvement to lightning strike. With grandmaster becomes removal with potential 6 life gain. Awesome against aggro strategies with limited application against ramps.

Foul-Tongue Invocation - A necessary stop-gap against aggro with awesome application against midrange and heroic. Decent application against some controlling decks.

Hero's Downfall - Slow removal for planewalkers and various big creatures.

Kolaghan's Command - Catch-all utility spell that will generally catch a small creature with an added benefit.

Anger of the Gods - Great aggro stopper with good application to ramp decks as well. Excellent life-gain potential with soulfire grandmaster.. Limited application against slower, control-style decks. Exiles Phoenici and Raptori.

Read the Bones - Deck tends to run out of cards. This is simply the best we can do to combat that.

Thoughtseize - Reasonable application against all decks and one of the few maindeck cards with strong application against control pre-board.

Goblin Rabblemaster - Comes in against control to apply pressure.

Soulfire Grandmaster - Provides excellent come-back potential against aggressive decks or slow-down in early game. Excellent combination with draconic roar and anger of the gods. Anti-aggro only.

Abzan Advantage - enchantment removal has several applications in standard including the obvious applications in Gx devotion and Jeskai combo as well as secondary applications like Courser of Kruphix and Boon Satyr. No real cost vs Erase.

Crackling Doom - 4th comes in against heroic decks and midrange decks in particular. Also a strong option against dragon decks.

Foul-Tongue Invocation 3rd and/or 4th copy to add slow removal and life gain against aggressive decks.

Anger of the Gods - backbreaking against aggro, particularly if soulfire grandmaster is involved.

Read the bones - 4th against control to keep the cards coming.

Gx/Gr Devotion:
In:
2 Abzan Advantage
1 Crackling Doom
1 Read the Bones
Out:
2 Bile Blight/
2 Kolaghan's Command
Notes: Fliers can just destroy this deck - some slight adjustments make this positive matchup a little stronger.

Heroic (Bant/Azorious/Jeskai)
In:
1 Crackling Doom
2 Foul-Tongue Invocation
1 Anger of the Gods
Out:
2 Hero's Downfall
2 Bile Blight
Notes: Crackling Doom is nuts against them and invocation gives mini-dooms 5-8. Try to get them to tap out to protect creatures for early anger of the gods.

Mono-Red/Jeskai aggro/Generic aggro or tempo:
In:
1 Anger of the Gods
2 Foul-Tongue Invocation
4 Soulfire Grandmaster
Out:
3 Read the Bones
4 Thoughtseize
Notes: The idea is to slow them down with life gain from soulfire grandmaster. Comboed with draconic roar or anger of the gods, this is highly likely to edge them out.

Low-Creature Control:
In:
1 Read the Bones
1 Crackling Doom
2 Foul-Tongue Invocation
4 Goblin Rabblemaster
1 Abzan Advantage
Out:
2 Bile Blight
4 Draconic Roar
3 Anger of the Gods
Notes: Advantage might be dead, but the alternatives are almost definitely dead. If they only have a few creatures, doom and invocation are a nightmare.

High-Creature Control/Midrange:
In:
1 Read the Bones
1 Crackling Doom
2 Foul-Tongue Invocation
Out:
4 Draconic Roar
Notes: So much removal should put them out of business.