This deck will use the synergy of demons with the addition of some angels, that, with the passive power of the corruptor, are also demons. There are demons who are stronger than Angels, or have the same power, but, with cards like fallen angel, witching hour and sites, the angels will have a good amount of power + ward and other effects
The overall strategy is use the demons and evil minions with the buffs they can gain to make good trades and get damage. The deck also has a good amount of spellcasters for an arcane barrage, or other good spells like pact with the devil, but also, to tap a shackled demon.
The deck works well with the minions being used with its strengths, but I think what make this deck have a lot of potential is doomsday cult, allowing evil to be cast from the top of your deck makes summoning demons much more fluid, and also allows you to focus on building your mana up for some more expensive minions. Of course, if you're facing someone that also has a lot of evil minions, you'll need to be Careful to where you position your doomsday cult, but in case you need, the deck also has disintegrate and other magic to deal with it.
So, good cards to have on your starting hand are: doomsday cult, fallen angel, the amethyst and ruby cores to help achieve the mana necessary for the bigger minions, or to be able to summon more minion with doomsday cult, Wich speaking of it, you can use the demonic contract to search for it, but remember that you'll need a elite demon to do it. It is Also important to hold sites that have 
so you can play the important cards that require 2 (F) threshold