Hearthpwn

Basic strategy is to use board clears and early minions to control the board and stay alive until the later game when you can start dropping your big bombs.

Frost Lich Jaina - Snowballs out of control once played if you can survive long enough which is easier than it sounds as long as the board is in a decent state.

Alexstrasza - Can be used as a heal OR can allow for the pseudo freeze mage strategy of set them to 15 then burn them down with spells.

Medivh, the Guardian - Creates huge tempo swings alongside cards like Firelands Portal, Flamestrike and Fireball.

Archmage Antonidas - Now, I didn't expect this to work that well since there are no obvious cards that it combos with. However, since very little hard removal is being played right now it's surprising how difficult opponents can find it to remove him without trading minions and he is often the MVP. Frost Nova can protect him and Primordial Glyph can often generate a second spell trigger as well with all the 3-cost and lower spells mage has access to.