For this encounter I used a Deathrattle Deck with [card]N'Zoth, the Corruptor[/card]!
The deck is pretty straightforward and it's really easy, but as usual, RNG can screw you over pretty hard! ;)
For dealing with his minions I used 2x Explosive Traps as well as 2x Corrupted Seer which made it easy to deal with his early minions and the 3 Kindly Grandmother he has on the board at the start of the game.
You can pretty much change every card you like, I just used this deck with the cards I had, but a lot of Deathrattle minions are viavle in this deck and replaceable!
Here is my video on how I beat the Heroic encounter! I hope it helps you guys out there to deal with the boss.
I wish you good luck and have fun on your adventure!