This may not be the best deck to defeat Heroic Sapphiron, but it's been proven to work.
How Does It Work?
There's RNG involved due to the fact that you need to rely on your damaging spells for the bulk of the damage against Sapphiron and you have no idea when they will show up. You also need to have moderate success with the minion summons.
- Keep enemy minions under control with spells like Blizzard, Cone of Cold, and Flamestrike.
- Play Mad Scientist to get the secrets out of your deck that will help protect you and give you minions.
- Mirror Entity is a fantastic card. It will give you a minion that has a great potential of not being dead since it will give you a minion after he's automatically used his hero power at the start of his turn.
- Nerubian Egg works much like Mirror Entity in that you should have a minion available next turn, or it will be attacked by Sapphiron and save you from taking damage.
- Pyroblast, Fireball, Frostbolt are your direct damage spells. Together, these will do a total of 38 damage against Sapphiron, not enough to straight up kill him. This is where minions will come in handy. If you need to use a Frostbolt or Fireball early on to remove a nasty enemy minion, you have a bit of flexibility, but then you're really hoping for the best case scenario for your summoned minions.