Mulligans
General Mulligans
These cards are good in every single matchup. They are both defensive and help you get faster to your combo.
Aggro Mulligans
In addition to the other cards that you keep in general, you are also looking for your anti-aggro tools to help you surive until you can pull out a Voidlord or to get to Bloodreaver Gul'dan and your combo.
Overview – Let’s Do This…
This is a very fun deck that deals quite a bit of damage and has a very powerful warlock shell. It has many anti-aggro tools at your disposal, and quite a few ways to draw to your combo. You can cheat out a Voidlord in the early game with cards such as Skull of the Man'ari and Voidcaller. You can get these quite consistently with the one copy of Sense Demons. I currently have a 79% winrate (33 and 9) with this deck, and I took it to legend this February.
The Combo:
This is a deck that requires a DOUBLE DISCOUNT from Emperor Thaurissan using Drakkari Enchanter. That doesn’t mean that this deck is not good. With the double discount, this lets you play Leeroy Jenkins + 2x Power Overwhelming + 2x Faceless Manipulator for a total of 9 mana and 42 damage. There is also an Ironbeak Owl included in case you need to get past a pesky taunt. You can play this with the combo, since it will only cost 1 mana.
Tech & Substitutions
This deck is very solid how it is, but if you find yourself looking for more damage, then cards like Darkbomb are extra damage or just a decent card for removal / getting through small taunts. Another good card which was originally in the deck was a copy of Tar Creeper. This was very useful in the hyper-aggressive matchups such as Kingsbane Rogue and Odd Paladin. The most cuttable cards are Mistress of Mixtures and Doomsayer. Any other draw cards (such as Loot Hoarder and Acolyte of Pain) would work well in the fast combo matchups or versus control.