If you’re looking for the Decks to Beat Lich King with All 9 Classes then check the images below.
Chakki was the first person I noticed to kill the Lich King with all classes and shared the list on his twitter so all credit goes to him..
Here are the decklists he used to kill lich king with Druid, Hunter, Mage, Paladin, Priest, Rogue, Shaman, Warlock, and Warrior:


Some of the battles are really tricky (Blizzard warned they would be hard). So, don’t be put off if it takes a few attempts and a nut draw to get through it.
The rewards is a new Paladin Skin – Arthus.
For the mage fight, use Kabal lackey + Counterspell during first turn, so you can stay with 30 health