Hearthpwn

I've been playing a lot of elemental mage and big spell mage in the last couple expansions, and through my experimentation, I think I've found a variant on big spell mage that shores up a lot of the weaknesses the deck has. This deck uses the standard big spell package for value and removal, but also adds a few cheap deathrattle minions to fight for the board early on against aggro, while utilizing Nzoth and Pyros to generate extreme value in control matchups.

I'm not a legend player by any means, I got this deck to rank 8 last season, and am currently rank 13, but I've experimented with variants of frozen's big spell deck, kibler's bright eyed scout deck, and this seems like a more consistent deck to me than those, that gives big spell mage a chance in this meta. This deck is, in my experience, better against aggro while also having absurd value to fight against control, but is pretty vulnerable to burst damage decks (raza priest) and tempo mage that runs counterspell.

 

Against Aggro

The early game minions of this deck won't control the board against aggro, but healing from mistress and plated beatle means its a lot harder for aggro to kill you by turn 5. This deck has so much removal you can be pretty loose with it against aggro, its ok to waste a dragons fury without getting max value, because then you can follow it up with a blizzard/flamestrike on 6/7, and still have way more value than the deck you're facing. Infested tauren, while not a good card on its own, actually deals with aggro pretty decently. Sometimes you'll still have a bad draw and just straight up lose to aggro, but most big spell mages (and most control decks in general) have that problem. If you survive to turn 10, infested tauren means you can play nzoth without dying immediately, though most games against aggro is over one way or the other before this point. 

Arcane artificer, frost lich jaina, and your deathrattle minions can help you regain health. Also remember that if you have an elemental on board and you play jaina, it gets lifesteal, which can help jaina be a bit of a safer play sometimes (this isn't an elemental deck, but its a side benefit of pyros and the free 4/4). Still, if you know the deck is aggro, you mulligan aggressively for your beatles and mistresses, while also keeping dragons fury, which is your best card in this matchup.

Against Control

This deck has four massive value cards: Frost lich Jaina, Medivh, Pyros, and Nzoth. If you can, try to wait to play nzoth until after you play pyros, because getting three 10/10s with lifesteal in a game really makes it hard for you to get outvalued. Pyros is a pretty safe keep if you aren't sure if you're facing aggro or control, because a 2 mana 2/2, while not good, isn't awful early game, and just having played pyros in the game makes your nzoth really strong. The other value cards are pretty self explanitory, Jaina's hero power is incredible and the lifesteal makes you really hard to kill, Medivh helps you fight for the board against other players insane combos.

Matchup Specific Tips

Cubelock: I'm pretty convinced that if I play this deck correctly, it has a good matchup against cubelock. However, I've also misplayed against cubelock a lot, so its easy to mess up this matchup. The main thing to keep in mind is: you really don't care about their voidlords. Never polymorph a voidlord, only polymorph doomguards and cubes that will spawn doomguards (and also rin, if you can). Also, save nzoth and try to get multiple pyros with it for maximum value. Use your other spells for other minions, you have so much removal and value in this deck you actually can beat any sort of control warlock or cubelock if this deck doesn't get burst down, it has a lot of healing, especially with frost lich jaina, so if you can get their bloodreaver gul'dan to give them back a bunch of voidlords and voidwalkers, you can win, because without the combo, warlock can't kill you.

Also, its important to note that skulking geist helps slow warlock down a bit (makes their combo harder to pull off), and gets them to fatigue faster. Try to play it early if you see an opportunity to.

Kingsbane Rogue: This is a weird matchup, and I think... it somehow favors the rogue. This game is basically you trying to flail wildly and get a water elemental to stick on the board, and freeze their face, while they use sap and vanish and try to mill your frost lich jaina. If you can get a water elemental to stick, you win, but you have to be cautious about blade flurry, sap, and vanish, which makes it tough. This matchup is also weird because you want to try to play as many cards from your hand as possible, and this deck isn't very good at doing that because cards cost so much mana. You also want to kill off as many of your own minions as possible, because that means you mill fewer cards when they play vanish.

To win, you have to make as many normally bad plays as possible and hope its enough. Its really weird.

Reno Priest: All hail the nerfs, because this one unfortunately favors the priest. This deck has healing, but its not quite efficient enough to make work, and it doesn't pressure fast enough, so priest is usually free to set up a 28 damage velen combo. Your victory conditions in this are a fast medivh in to a quick kill (while hoping they dont have removal or anduin), or an early frost lich jaina to grind them out and always staying at 30+ health, then get massive nzoth value with a bunch of 10/10 lifesteal minions. Be careful with pyros, don't let priest steal it until you've seen them play their potion of madness, since that gives priests more cards, and steals one of your victory conditions.

Spiteful Priest: Raven familiars obviously won't win you any cards in this matchup, but as soon as you see the mind control or free from amber, you can want to play and kill off pyros before they get to 10 mana for a mind control on pyros. This deck has a good combo of value and tempo, but you have dragons fury, meteor, and a lot of huge removal spells. The Blizzard/flamestrike combo or blizzard/dragons fury is pretty nice in this matchup, especially if they pull a Ysharj from spiteful summoner. Basically you just gotta survive until they're out of threats and you aren't, and make sure they don't mind control pyros until you've at least killed the 2/2 version for nzoth value. This matchup feels pretty even to me, maybe this deck has a slight edge (maybe not though).

Jade druid: Obviously geist is going to be great here, mulligan for this. If you don't draw geist (which is unfortunately possible, the deck doesn't have that much card draw), an early medivh can put enough pressure to win you this matchup. If you do get geist, you can outvalue it. Save a polymorph for Aya to slow them down a bit.

Tempo Rogue and other aggro: Matchup is very early draw dependent, but basically, try to mulligan for dragons fury and your tiny minions. You can pretty much treat tempo decks like aggro decks, you win the long game, its just about getting there. If they kelleseth/shadowstep turn 2 in to leeroy/shadowstep turn 6, there's not much you can do, but I mean, there isn't a deck in the game that consistently beats tempo rogue with a god draw. This deck has the dragons fury, blizzard, and healing to beat it otherwise, and this deck can prey against other aggro matchups. It feasts on paladin, is good against hunter, is amazing against shaman even if you don't draw the geist, and can beat pirate warrior with a decent draw. You'll lose some simply because the deck has too many expensive cards to beat aggro every time, but it feels solid against aggro.

Tempo Mage: This is a pretty bad matchup because of counterspell. Your small deathrattle minions deal decently with explosive runes and mirror image, but you need to save the coin for a counterspell, and hope to draw well. If your turn 5 dragons fury is countered, there's not much you can do in this one.

Other Options I've Considered

Bloodmage Thalnos: I don't have Bloodmage Thalnos, but I'm sure he'd be good in this deck. Maybe replace the acolyte of pain. The spell damage would be pretty nice, though the deathrattle with nzoth is... not as good as it appears at first glance, but I'll get to that later.

Dragoncaller Allana: Again, don't have this card, but it would be good in this deck. However, it would be tough to fit in. This deck has space problems already, and it has enough value as is. Maybe it could be used over a flamestrike or something, or replacing medivh.

Loot Hoarder: I experimented with loot hoarder for a while, and there is some benefit to drawing your key cards faster in control matchups. However, I noticed two big problems. First off, adding more deathrattle cards means you have less of a chance to get back pyros with Nzoth, and in control matchups, those extra two pyros are really useful. Secondly, this deck goes to fatigue a fair bit, and drawing after you play nzoth isn't necessarily great, because it can push you further in fatigue damage. Also, a 2 mana 2/1 is not good against aggro.

Shimmering Tempest: It was in the original decklist, but a random spell is really inconsistent, more deathrattles in the deck means a lower chance to get back pyros, and a 2 mana 2/1 isn't very good against aggro.

Leyline Manipulator: In my experimentations, I've tried using this with shimmering tempest and pyros, but the cost discount comes at a point in the game where you don't need it, and a 4 mana 4/5 is fine, but nothing special. It was one of the weaker cards in the deck, so I removed it.

Spiteful Summoner: This was in the original version of the deck, but I removed it in favor of the free 4/4 elemental. This gives you a lot of value, but the deck didn't need more value, it needed more consistency and tempo. It honestly just doesn't need this card to win.

Tar Creeper: Right now, I'm considering removing one mistress and putting in a tar creeper instead, but haven't tested this yet. Still, this is a defensive elemental taunt, which could be very useful. It could also be used over acolyte of pain to really tech against aggro, but I think this deck does need at least a little draw.

Ice Block: I don't think this deck needs it. 3 mana do nothing isn't that good the turn you play it, it doesn't help much in a control game, because it doesn't add value to your deck, and dragons furying an ice block is awful for this deck. 

Arcane intellect: I feel as though acolyte of pain is just better than this card because of dragons fury and raven familiar.

Odd Tech Options that are in the deck

Pyros/Nzoth: Pyros just gives you a way to beat control decks, and with nzoth, its insane. Its also not an awful card against aggro, its certainly not good against aggro, but its playable as a 2 mana 2/2.

Skulking Geist: Gives you a way to beat jade druid, while also hitting dark pact, evolve, jasper spellstone, and the rare inner fire. Its worth having one for that.

Infested Tauren: This is not a good card on its own, but its main purpose is to make Nzoth not a dead turn for the board when you play it, and honestly isn't bad against aggro. Obviously not going to carry the deck on its own, but before I put this in, I had a few games against rogue where they had one minion out late game and I was on low health, and I really wanted nzoth to revive my mistresses and plated beatles, but couldn't because it didn't bring back a taunt. As the only taunt/deathrattle neutral card in standard format, this sneaks its way in to the deck.

Acolyte of Pain: This deck doesn't need too much card draw, but having one acolyte can help avoid it stalling out, and reach its key cards faster. I've tried having two, but when I do, I feel as though the deck isn't as solid. Against aggro, it needs its early game defense, and against control, it needs its value. This card provides neither one, and your high value spells make up for card draw. I put in acolyte over arcane intellect for dragons fury and raven familiar value.

Polymorph: This is mainly anti-warlock tech for doomguards, though it also hits aya and other high value cards in control matchups. It makes dragon fury and raven familiar a bit weaker, but as long as warlock is in the meta, I think its worth running. This would be replaceable in a different meta.