Hearthpwn

Puzzle #4 in 3 easy steps

1.  Play Carnivorous Cube on Mistress of Mixtures.
2. Play Dark Pact on Carnivorous Cube.
3. Play Cataclysm.

Puzzle #3 - Pesky Priest (alternate, more fun strategy)

1. Cast Light of the Naaru on Auchenai Soulpriest
   
2. Cast Elixir of Life on Lightwarden
3. Play Breakout
4. Attack Abomination with Auchenai Soulpriest
5. Play Earthen Ring Farseer, targeting self
6. Cast Binding Heal on Abomination
7. Attack Abomination with Mistress of Mixtures
8. Attack Abomination with Tournament Medic
9. Cast Circle of Healing
10. Use Lightwarden to attack Abomination.
11. Use hero power on self

This pack was pretttttttttttty good.

Card art is a homage to the room of winged keys in Harry Potter and the Philosopher's Stone.

Expansion speculation:

Expansion 1: The tree roots and pool is reminiscent of the Well of Eternity and the Emerald Dream. Combined with Lunara as new hero, I expect something night elf/druidic in theme.

Expansion 2: Art design is similiar to ethereal/nexus-lord in WoW.  Bottom of picture appears to be a field of stars. I expect this expansion to be either ethereal or void lord related.

Expansion 3: The primitive paint aesthetic is reminiscent of troll or orc symbolism in WoW.  This one is hardest to predict. I expect something tribal - beyond that hard to say.

I subbed out shieldbearer and righteous protector for divine strength, and swapped out repentance for consecration.  The real trick to this fight, which I haven't seen mentioned, is that the AI plays really poorly into noble sacrifice.  A typical turn 4 or 5 AI play is to use the card that gives +2/+2 to his minion which the AI then tries to throw into your dragonhawk.  Noble sacrifice literally wins the game because the AI spends all its mana assuming it is going to kill your minion.

I didn't have Avenging Wrath but I agree it's worth including, ideally the deck would probably include 2, and drop a MCT and/or a shielded minibot

I beat this boss in spectacular fashion with a wombo combo Paladin Deck.  Mulligan for lay on hands and either a 1 or 2 drop, preferably echoing ooze.  Then wait for him to play Millhouse Manastorm and cycle your deck for insane results.  An alternate win condition is to get lucky with Mind Control Tech and stealing something like Hogger which the AI can't deal with easily due to not having spells.  It may be necessary to stall with board clears like Equality/Consecrate or Wild Pyromancer/Consecrate to set up a later combo when the AI plays Millhouse.