Hearthpwn

 

 Update (Jul 3): I ended June at Rank 2 with this deck. Since I posted it I have substituted Molten Reflection and 1 Exploding Rune for 2 Amani Berserkers. I love Molten Reflection but its value is very situational and was making the deck too bottom heavy. I'd love a second Exploding Rune, but too many secrets were slowing the deck down. 

Update 2 (Jul 6): The deck was simply not as powerful without Molten Reflection, but I couldn't fit it in, until it hit me: If Ethereal Arcanist is only valuable buffed, why not replace one of them with the chance to have 2 buffed ones? So I switched 1x Arcanist for 1x Molten Reflection and the deck works a lot better. I also added a little Molten Reflection section in General Principles.

Update 3 (Aug 3): Boomsday Project is less than a week away, and I honestly don't know if the meta will have a spot for a midrange deck like this, between all the crazy Deathrattle Hunter shenanigans and Shudderwocks and Druids looking as strong as ever. Never the less, this is my first attempt at incorporating a few BDP cards. Unfortunately not many of the new mage cards are relevant to a tempo deck, especially on this versions that is unlikely to get more than 2 cards out of Stargazer Luna.

General Principles

This isn't a burn deck, as it lacks the small high-damage spells that would supercharge your Mana Wyrms in the very early game. Instead, it is designed to have enough utility and board presence to survive into the early endgame. Nevertheless, it is still a tempo deck. Either you have Aluneth and you are dead from fatigue around turn 14, or you don't, and you are dead around then anyway because you can't generate enough value without it. 

Your play is centred around maintaining board control through correct trades and secrets, while going face as much as possible, bringing the opponent low enough to be finished by double Fireballs or Pyroblast. Alternatively, Ethereal Arcanist can be a win condition if allowed to remain on board buffed for a couple of turns. 

Aluneth

Don't play it on turn 6 unless there's absolutely nothing better to do, or you are completely out of cards. A dead turn can swing the tempo against you, and 7 mana most likely isn't enough to play 3 cards anyway. Playing it on turn 8 or 9 together with something else gives you the most value, especially if you managed to save one or both Apprentices.

Aluneth turns are the most important in the game. You have a lot of choices in hand and you need to utilise every mana with extreme care. Always prioritise minions over spell burn, ideally cramming all your spell burn into one glorious turn with 1/2 Apprentices on board.

Secrets

The substitution of an Explosive Rune for a Mirror Entity is an important part of your strategy, especially against EvenLocks (early game), CubeLocks and Recruit Hunters (midgame), and Druids (late game). Beyond potentially capturing something valuable, ME can be used together with ER to bluff a Counterspell. Just always be mindful of how you layer your secrets: they activate in the order they were played and ME doesn't trigger if the minion doesn't survive ER (both options have merit situationally): 

-ER then ME: Say your opponent checks the secret with a Firefly. ER goes off, ME doesn't. They now think it is Counterspell, which stops them from playing a valuable spell, or they play Lich King. However, if they play Lich King directly, it goes to 2 health and you both have a 2 health Lich King.

-ME then ER: Firefly gets copied, the original goes splat, you now have a Firefly facing your opponent's Lich King. Congratulations. Alternatively, Your full health Lich King is facing a 2 health Lich King. 

I could only fit 3 secrets in the deck, which is not ideal but has the side benefit of making your Arcanologist very predictable. The Keysmiths pick up the rest of the slack. This is suboptimal both because of the RNG involved, and because the opponent knows a Keysmith secret can be anything and are unlikely to throw anything important at it. On the other hand, their situational utility is limited only by your imagination: The Rogue or Paladin haven't played Cold Blood/Blessing of Might yet? Spellbender. You can make sure the only thing that'll hit your face is a huge minion? Vaporize it. You really needed Counterspell for a Druid's turn 5 but you only got Mana Bind? In the long run it might be for the better, even if you just get a Jasper Spellstone out of it.

One last note: Especially against control decks, there's value in playing a secret that would be hard for them to trigger (Vaporize or Ice Barrier f.e.) just to feed your Ethereal Arcanist.

Molten Reflection

In the context of a tempo deck a 4 mana card is extremely expensive. It is actually as, or more expensive than all the minions in the deck other than Leeroy. Then why add it? Because in the current meta keeping any one powerful minion on board is very hard, there is too much removal. If you managed to do so pushing the advantage by copying it gives you the value you need to win. Three general use cases:

1. Finisher with Leeroy. 12 damage for 9 mana, provided there aren't any taunts in the way. Has the added benefit that not many people expect it. Playing against an aggressive mage deck most people play around Pyro at turn 10, 2 extra damage one turn early is all it takes a lot of the time.

2. Duplicating a buffed Mana Wyrm or Ethereal Arcanist. It took a lot of work to keep them alive long enough to grow, won't happen twice in a game since our horizon is ±14 turns.

3. Duplicating a minion captured by Mirror Entity. Any minion that costs more than 4, it's pure value. In specific cases (Giants/Lich King) it can also be used as an effective, if inelegant, way of clearing your opponent's original of your copy: Molten Reflection and smash the first copy into the original.

Of course it can always be used situationally as an emergency card as well, if you need to keep up with the board, sometimes a second Spellbreaker is all it takes...

Mulligans and Class Strategies

Give priority to minions over spells

Always keep: Aluneth, Arcanologist, Amani Berserker

Always keep Kirin Tor Mage together with Exploding Rune (especially if you have Coin)

Always keep Mana Wyrm if you have Coin or one more small spell

Only keep Apprentice if you have Mana Wyrm + Glyph + Coin. They die fast and in most cases you are better served saving them for Aluneth turns. 

Against Druids: Keep Polymorph. You won't need it until turn 8-9 but you only have one and if you don't have it on hand you are screwed. Keep Keysmith and Counterspell, but don't waste them before turn 5-6.

You need to interrupt their play as much as possible, making them play around secrets and clearing your board, so they don't get too far ahead of you on mana. Try to catch at least 1 Nourish with CS/MB and force them to use at least one Naturalise on you.

Save one Keysmith/Counterspell for turn 9+ to prevent/delay Ultimate Infestation or Hardronox+Naturalise. Save Mirror Entity for turn 8-9 to catch a Primordial Drake/Sleepy Dragon/Lich King/Malygos. Have Polymorph and a silence(or Frostbolt) ready for turn 9 Oakheart/Dragonhatcher.

Against Hunters: Keep Kirin Tor Mage (best minion to check traps with), Mirror Image (in case they are burn OddHunters).

As much board presence and face as possible. Against Hunters Mana Bind => Counterspell as their spells are excellent and you can counter most of their effects with the 0 mana copy. Make them feel they need to go DK for the board clear/armor as fast as possible, throw a ME or Frozen Clone and you are done.

If it's not a pure Spell Hunter never play ER past turn 5, or you giftwrap them a Recruit. Save Spellbreakers for the Ooze and/or Kathrena.

Against Mage: Keep Frostbolt, Mirror Image (in case it's mirror/murloc), Counterspell, Keysmith (in case it's not).

Most control variants don't stand a chance. Their lowest-cost spell is Polymorph, so putting up more than one Counterspell wrecks them. Kill/silence Arcane Artificer with extreme prejudice (even spending a Fireball on it might not be overkill). Mirror Entity past turn 7 will always give something meaty.

If it's an agro deck, play carefully and value trade, you have more utility and you should outlast them.

Against Paladin: Keep Mana Wyrm, Primordial Glyph (to get some aoe), Spellbreaker

If it is quest/Even Paladin keeping their board clear is more important in early game than developing yours. It's worth it to spend 2 mana on Hero Power every turn/go off-curve to keep their board completely clear. It'll slow them down far more than you. Save one Spellbreaker for turn 7/8 (Lynessa or Tyrion).

If it's Odd Paladin try your best while expecting your almost inevitable demise. I've won against them, but it involved both Glyphs giving me Flamestrike and/or a lot of magical topdecking.

Against Priest: Keep Counterspell, Spellbreaker, Polymorph

Use Polymorph as soon as possible, use it even on a Loothoarder. If it's quest Priest it will mess up their Twilight's Call, if it's an OTK Priest it'll mess up their everything. 

If it's a buff Priest prioritise clearing the board and don't use your Spellbreaker too fast, make sure that at least 5 mana-worth of buffs have been used on the minion you silence.

Counterspell up for turn 7 Psychic Scream, but honestly, they have so many cheap spells you're better off bluffing it with a Mana Bind, you might get a Shadow Visions out of it.

Be mindful that ME-ER Velen results in you having a full health Velen while your opponent has -5 to their face (ER goes to 12), while ER-ME Velen results in you both having 1 health Velens

Against Rogue: Keep Exploding Rune, Mirror Image, Spellbreaker

Should be an easy matchup, especially since a lot of Rogues have the bad habit of clearing the early board with their face. Protect your valuable minions from easy trades but mostly go face as they don't have healing and will turn defensive fast.

If it's Kingsbane Rogue save one (ideally both) Frostbolt to use on their face after their weapon has gotten Lifesteal and >4 attack. They have a rather slow early game so 1-2 turns should be enough to finish them off.

Against Shaman: Keep Frostbolt, Counterspell, Keysmith, Spellbreaker, Ethereal Arcanist

Good god, their board clears have board clears. In this more than any other matchup Arcanist is key as it can easily survive Lighting Storm. 

Go for the face as much as you can. You are unlikely to burn them down fast enough, and they can play around Counterspell easily, but they'll have to waste mana on heal/make them use Volcano.

Bluffing with Mana Binds is valuable since a lot of the cheap spells they use to pop secrets with are Overload cards.

Against Warlock: Keep Mirror Entity, Spellbreaker, Frostbolt, Polymorph.

Not many classes are as considerate as to kill themselves, but damn... EvenLocks.

If you see them playing nothing for the first 2 turns, they have Mountain Giant in hand, play Mirror Entity and as long as you have a way to get rid of their Giant efficiently it is pretty much unrecoverable for them. Even if they are not as careless as that, they are consistently at very low health, relying on taunts to protect their face. Play your Spellbreakers correctly and it is an easy matchup.

If it's Cube/skull Lock never play Exploding Rune after turn 5, obviously.

They always check for Counterspell with Defile, so bluffing with Mana Bind could make them clear/take a huge chunk out of a board they control.  

Against Warrior: Keep Spellbreaker, Polymorph, Keysmith, Frostbolt, Exploding Rune

If it's a Rush Warrior it should be an easy matchup. Just silence their most dangerous minions and kill them fast.

Quest Warriors are tricky because of the waves of Taunt minions. Don't Mirror Entity before turn 7, but it might be worth it to Frozen Clone with a Keysmith at around turn 4 to get a couple of Saronite Chaingang, they'll help you keep up with the board.

Never overcommit on the board, most of our minions have just 3 health, so there are at least 4 board clears on most Warrior decks.