I have defeated the lich king with all 9 classes. Here is the decklist so that you can do it as well! Hope this helps!
PS: Copy this: AAEBAaoIBNcPhBenzQKLzgIN7gHbA/4D9QT+BdAH8AenCJMJvxfjuwL2vQLHwQIA
and then create a deck. It will ask you if you'd like to automatically build it. Happy hunting!

Custom Shaman

Class: Shaman

Format: Wild

1x (1) Deadscale Knight

2x (1) Grimscale Oracle

2x (1) Murloc Tidecaller

1x (1) Sir Finley Mrrgglton

2x (2) Devolve

2x (2) Flametongue Totem

1x (2) Ice Fishing

2x (2) Murloc Tidehunter

1x (2) Vitality Totem

2x (3) Feral Spirit

2x (3) Hex

2x (3) Lightning Storm

2x (3) Murloc Warleader

2x (4) Call in the Finishers

2x (5) Bloodlust

2x (5) Volcano

2x (7) Everyfin is Awesome

AAEBAaoIBNcPhBenzQKLzgIN7gHbA/4D9QT+BdAH8AenCJMJvxfjuwL2vQLHwQIA

To use this deck, copy it to your clipboard and create a new deck in Hearthstone