Just tried this deck as i love the concept of demons in hearthstone, with many good cards like Voidlord , Bloodreaver Gul'dan , etc. being in the wild format, i thought that i should make a deck around it bringing a lot of value. This deck has issues with priest (*cough* resurrect priest *priest*) and some aggro decks.
For the aggro decks i included Defile as it helps a lot in the early game to keep yourself alive in order to use your demons.
Ectomancy works great with Mal'Ganis making the enemy deal with not only one but two of this essential card in your deck, using Bloodreaver Gul'dan will bring you the two mal’ganis that died (if the enemy manages to kill two of them) and if you still have a copy of ectomancy you will get two more copies of that minion, depending on the board space. If you used up all your ectomancy cards you will still have 2 mal’ganis on the board buffing your other demons with +4/+4 stats and making your hero immune.
I also added Jumbo Imp as it can decrease a lot from the void walkers and you dont have to pay anything with skull of the man’ari, void caller and the possessed lackey in your deck. It is very good to put pressure on your opponent, it replaces mountain giant and benefits from bloodreaver gul’dan, mal’ganis and ectomancy.
This is my first deck and if you have any opinions on how to optimize this deck i will gladly accept them.