Hearthpwn

Hi I'm DrGonQ, I want to show you the deck I used to get rid off HC Sapphiron.

Strategy

The goal of this boss is to survive, killing and freezing his minions and fatigue him to death

Sapphiron will ALWAYS do first Frost Breath killing your minions and then he will attack and play his cards. (Remember this for your Duplicate)

Mulligan for low cost cards like Arcane Missiles or Frostbolt

It doesnt matter if you mulligan a Fireball or an Antique Healbot just keep it for later.

You MUST use Bluegill Warrior to kill his Faerie Dragon

You MUST use Fireblast on his Loot Hoarder. If you  have cleaned his minions and still got 2 mana Fireblast the face (as possible, you should clean minions first)

You MUST use Frostbolt or Forgotten Torch on his Skeletal Smith and Mana Wyrm

You MUST use Fireball and Roaring Torch on his Necroknight ONLY when Spectral Knight is next to him.

Flamestrike should be used on at least 4 minions (and you can kill them all) specially Dancing Swords and Azure Drake, Flamecannon and Arcane Golem are our friends here.

You can combo Flamestrike and Explosive Sheep for his Spectral Knight too.

Arcane Missiles is good against Shade of Naxxramas

Use Vaporize on annoying Spectral Knight

NEVER get too low HP, expect a Pure Cold , health up using Antique Healbot , make sure u can Duplicate it for extra healing.

Use Brann Bronzebeard combo with Antique Healbot for emergency heal. 

Effigy can be used too on Antique Healbot to get a 5 mana minion to trade wisely (Will die next turn remember)

Use Ice Barrier Frost Nova and Cone of Cold to prevent a lot of damage

Spellslinger and Ethereal Conjurer can give you some useful spells (or not). I got Echo of Medivh

You MUST ONLY play Pyroblast when Sapphiron begins to Fatigue in order to accelerate his death.

Feel free to give me feedback and poste your opinions, changes and experiences.

Hope you like it and you find it helpful. Good Luck

EDIT: I realized that Kirin Tor Mage is useless so I replaced it for Arcane Intellect. Ice Block or another Vaporize will help us.

EDIT2: I made a video following the strategy and won after a few tries. :D