This is the deck I'm currently playing at Diamond 3 with a 8-0 winrate since I crafted it.

The early game is a little bit weak, so just try to survive until you can cast your powerhouses.

Dragoncaster is key. Do not hesitate to cheat out a Puzzle Box of Yogg-Saron at any time in the game. Speaking of which: I know a lot of people don't like this measure of extreme randomness, and I'm definitely one of them. However the card is beneficial 80% of the time, does nothing special in 15% of the time and loses you the game outright 5% of the time. So I would say it's pretty much worth playing.