Sorry this deck is just not viable at ALL right now.  Tried it in Casual and was 0-6 with it.  Used your mulligan guide.  I usually ended up with my opponent having the board flooded and me with nothing because of all the low health minions that don't do much but card draw other low health low damage minions.  I rarely saw my ironbeak owls so saw taunt city most of the time too and again was unable to get through the taunts.  Keep banging away though I'd LOVE a GOOD shadow priest deck.  This one is not one thought right now.

I don't think an aggro deck with this mana curve can make well. U need to draw well.

I struggle to understand the reasoning behind light warden and northshire, since the only healing you have is your hero power, which doesn't last long. I found they just became dead cards

That comment sucks. Use a modicum of logic or reasoning at least. It's a community not a middle school.

Diggin' this deck.  I dropped the  Blood Knight x2 and Molten Giant x2 and replaced them with Shieldbearer x2 (for the low health minion protection) and Argent Commander x2 for the added rush/break through.  It's doing well in the 16-14 rank window so far. 

/// EDIT ///

May have spoken to soon...just as I reached 14....I'm back to 15 and on a 5 game losing streak. It's fun in the sense that it is different than the b-o-r-i-n-g aggro/control meta that has existed w/ this game for so long now (HS is the least varied tcg I've ever played (out of over a dozen in the last 6-8 years))....but because HS lacks that diversity in deck types and it's ALL about aggro (or control), decks like these just seem like more of a flash in the pants unfortunately.

Keep in mind...I'm referring to the modified deck, not the original deck.

I have all of these cards and have a question. I do enjoying putting two moltens into my deck when my Hero is a Pally. Nothing better than 20x2 straight to the face with a bit of random good luck. Doesn't happen very often but still funny as hell.

Other than the Pally, or the possible mid game Molten drop with mid range hp and 2 innervate in druid decks, I have NEVER pulled a molten from any of my decks when I needed them. To change your deck up a bit, I have pulled both Moltens and replaced them with Flesheating Ghoul and dropped one Blood Knight (dropped because normally I've only been able to get one of them on the board to take Shields before being destroyed or AoE removing all shields before I can play it) and replaced it with Onyxia.

The Combo is dropping both Flesheating Ghoul, Knife Jugglerand one Defender of Argus on round 8. Then on 9 Burn the Defender on an enemy minion, Onyxia comes out to play, summons her babies, Knife Juggler does his thang, and wait for 10. Of course I know that all of this is very dependent on RNG, opponents skill/deck, and a bit of luck, if I have a good portion of my combo still alive at 10, I let my cat walk across my KB and win.

In your opinion is this a viable swap out/combo?

Surprisingly enough, it would probably make for a better deck due to the unreliability of Molten Giants. I have actually thought about using Sea Giants in replacement, although Flesheating Ghouls with Onyxia is fine (and probably a lot more consistent), due to being a big drop and filling your board with minions (in the late game, where Priest don't have reliable card draw, this is pretty important). 

This "aggro" deck is inferior to any others. Not sure why I would ever choose to run this over some of the other options unless I just want to struggle by forcing a round peg in a square hole.

Thanks for posting this deck.  It's a fun and refreshing take on Priest.  I get tired of the L   O   N   G games with Priest control.  This one throws people off too because they don't expect it.

If i dont have shadow form at the moment can I swap them out for auchenai?

Decks called shadowform for a reason :P

Auchenai has a lot of problems in this deck, mainly in it being a minion that grants damage to healing. This means it's not permanent, unlike Shadowform, and would only be useful if the opponent doesn't remove it. Another major flaw with Auchenai is its cost - 4 mana. To combo with your ability, you would need to play her at turn 6, far too slow for this deck. The final reason I run Shadowforms is its ability to give you a 3-damage hero power in the mid game, where you've run low on cards and run over your opponent with minions.

That being said, Auchenai could be a (temporary) replacement for Shadowform, however, if you do not have Shadowforms, I would recommand using Lightspawns instead. (You can also use Thoughtsteal...? Just a thought, need more experiments with it.)

Thank you very much. Makes a lot of sense. Just pulled one in my pack gonna craft another one right now.

Try replacing a Blood Knight for it

Replace it with an Argent Squire then.

2 Mind Blast, 2 Holy Fire, 2 Shadowform, but no Velen?  

Went from 10 to 5 with it then called it a day. :D

Also if ur running defender and owls, you should think about adding ancient watches considers their stats/mana

I think running Ancients in this deck is a bit too slow, since you already have a ton of 1/2/3 costs to rush the face with. You should try it out and tell me how it went. :)