Hearthpwn

The intent of this deck is to control the board until you can deal 10 damage and are able to pull off a Prophet Velen/Mind Blast combo for another 20.  I'll state right up front, I make no claim that this will get you to legend, but you should find some success on the ladder and you should have fun with it.  I wanted a fun deck and to use Prophet Velen/Mind Blast effectively.  However, half the fun of any deck is winning and I have moved up a few ranks using this on the ladder so far.  

This deck is updated to have board presence and a variety of priest spells for board control rather than relying solely board clears.   So this deck is now closer to a normal control priest and can win without the combo, hence it's more consistent.   Once you have Prophet Velen  and at least one Mind Blast in hand OR both Mind Blasts in hand, drop Emperor Thaurissan to decrease the cost and set up for turn 8+ combo.  

It also now has potential to do 40+ damage in one turn by dropping Emperor Thaurissan with Prophet Velen, Mind Blast x2, and a Faceless Manipulator in hand.  If you're lucky enough for this to happen, you can drop Prophet Velen x2 for quadruple damage the next turn, a feat I have managed more often than I thought possible.  

Play style is straightforward control priest using board presence, spells, and board clears until you have the combo.   Northshire Cleric is of course your draw engine, but Thought Steal and Azure Drake are there to keep your hand full of options as well.  Acidic Swamp Ooze provides early board presence and counter weapon use.  One Auchenai Soulpriest and one Hole Nova are the two board clears to keep from getting over run.   Mind Control Tech and Stampeding Kodo are there to provide both board control and presence.  

NEVER use  Mind Blast without Prophet Velen unless it's a killing blow.  One healbot and your Mind Blasts are basically a complete waste.

Alternatives:  Since the goal of the deck is to buff Mind Blast, legendary cards are necessary.  Otherwise it would take five minions to get the +5 spell damage for the combo.  And, if you can get that kind of board presence for spell damage minions, then you probably don't need mind blast at that point to win.

[card]ragnaros the firelord[/card] can be replace with anything.  I didn't pick that card for any particular reason.

Malygos can be added  to double your chances of getting a buff for Mind Blast or used as a replacement for Velen if you happen to have the "wrong" legend.  Setup is the same as Prophet Velen and you get the same 20 damage, but you need to have all three in hand when you drop Emperor Thaurissan to get the total cost down to 10 mana.

Alexstrasza can be added as an additional setup step to ensure your opponents life will be under 20 for the combo...or for emergency healing if you're in trouble.  I've found that getting the combo off before turn 10 is unlikely anyway, so this is certainly an option.

 Also, I took a significant break from the game when GvG came out, so there are plenty of card from GvG and BRM that provide better board presence and/or control that I don't have.  For instance, Dark Iron Skulker is worth considering to replace Holy Nova healing with board presence, or to replace Stampeding Kodo to clear multiple minions instead of one.