So, I honestly didn't expect this guide to get any attention, so much to my surprise when I saw it on the front page! This deck is very similar to Hyp3d's freeze mage list from GvG. His list can be found on this video, and he also goes on to do a series of games with the deck to help show how the deck should be played. In the videos his list is +1 Pyroblast -1 Explosive Sheep.
So for those of you that don't know, Freeze Mage is an archetype based around stalling the game out with high value board clears, (Doomsayer, Flamestrike, and Explosive Sheep) freeze spells, (Cone of Cold, Blizzard, and Frost Nova) and secrets, (Ice Block, Ice Barrier, and Mad Scientist) while you draw through your deck with large amounts of card draw. Eventually you draw into Alexstrasza and your other burn spells.
So I decided to give Emperor Thaurissan and Malygos a shot in fereze mage, and damn am I impressed! These two cards add a lot of flexibility to you end-game, giving you oppurtunities to get lethal without Alex, something that could rarely be said for Freeze mage in the past.
Also, if you guys would like to see a Budget Freeze Mage I can put one of those together for you guys! Let me know if you guys wanna see one.
Polymorph: This one can be subbed in if you get tired of dying to Ragnaros the Firelord. Rag's damage cannot be frozen, and therefore he presents a huge problem. Thankfully, Polymorph turns him into a lovely little sheep.
Antique Healbot/Illuminator: These healing cards can be very useful in aggro matchups if you don't find explosive sheep to be doing enough work. Both cards provide healing that can save you from the persistence of hunter's hero power or the spike from mech mage. They have their upsides and downsides but in general I think the Antique Healbot is better.
Pyroblast: Pyroblast helps in the slower games, especially against classes with life gain. If you find yourself facing lots of priests, paladins, and warriors, teching in a Pyroblast might be helpful, but you might want to consider another deck archetype, as freeze mage does not do well against decks with large amounts of life gain.
I jokingly say that when you're mulliganing for freeze mage you keep anything that has the words "draw a card" or "scientist" in it, but its actually fairly accurate. If I say to keep card draw in the below sections, I mean keep card draw and Mad Scientist. In most situations, Arcane Intellect does not count as a card draw card in most situations because it doesn't give any minions to soak early damage or trade into your opponents minions. I also prefer to save Bloodmage Thalnos for burn, but against some matchups (matchups with low life gain) this isn't necessary and he can be used to cycle a card.
Assume it's Mech Mage, and keep the explosive sheeps if you see them, in addition to Frostbolts and card draw, scientists. Mech mage is a fairly good matchup for freeze mage, especially if your Doomsayer or Explosive Sheep gets Mirror Entity'd.
Thalnos: usually cycle
No shaman deck is the same, but this is an alright matchup overall as long as RNGesus doesn't totally hate you and your card draw. Keeping a sheep probably isn't a terrible plan, as it kills totems and other small shammy drops, butHaunted Creeper makes sheep much weaker.
Mulligan for Card Draw and maybe sheep.
Thalnos: Usually cycle
Thankfully most paladin decks I've run into these days are running less healing than the healadins of old, and this matchup has become a little better as a result. Archmage Antonidas may be necessary to create enough Fireballs to cut through a Lay on Hands or Guardian of Kings. Explosive Sheep is important here to kill the dudes, so I would keep one in the opening hand if I saw it. If yu find yourself up against a lot of paladins I may suggest subbing in a Polymorph, as Tirion Fordring can be annoying to deal with safely in some situations.
Thalnos: burn or cycle, depends on when you draw him. If I draw him turn 8, I'd probably save him until burn, but if you get him on turn 2 then just use him to cycle. Don't keep him in the opening hand.
Mulligan for card draw and sheep.
This guy was the reason that freeze mage was bad before GvG! (actually just Flare) Now its time we get our revenge! Hunter isn't too badof a matchup, unless you get very unlucky. Explosive Sheep is powerful here, keep it in the opening hand. Don't be afraid to Alex yourself to heal; Hunters usually won't be able to remove her, and you can just repeatedly smack his face until he dies.
This is the tough one. To be honest, this match up probably isn't worth your time playing. Warriors build up armor, and lots of it, and freeze mage just doesn't have the damage to get through the armor that warrior has. If you do decide to play it, mulligan for the usual, but sheeps are not helpful here.
I usually concede when I see warrior, but if you're feeling lucky you can give it a shot.