Hearthpwn

This boss was a difficult one, and requires a fair amount of good rng to complete. 

My initial thoughts was For a mill deck, but those don't exist i standard, so I had to come up with this instead. You want to just survive, drag the game on as long as possible, using your clears and heals wisely. Make sure that you dont have both mirror images die, as that puts you in a poor situation when you start to run out of cards, and kill/heal any of your minions that are on 1hp. 
Eventually the boss will draw out his deck, and you should still have another 8 or so turns before you do, if you don't have any more mirror images. With that and a few smacks to his face you should be able to win, but multiple tries may be required.