Hearthstone: The Enduring Handlock
This type of deck for the Warlock was a powerful contender even before the Goblin vs Gnomes expansion was released. This decks late game is extremely powerful and is suited well against control and aggro decks. Most of the time you will often lifetap through the first 3 turns as this deck has very few 2 drop and 1 drop creatures. Lifetap costs 2 mana and will damage your hero for 2 and draw you a card.
This 4 cost creature has a unique ability that makes it more powerful in the Warlock deck than others because of the Warlocks Lifetap ability. This card has 4 attack and its health is based on how many cards you are holding in your hand when you play it. Often times the Warlock will Lifetap twice in the first 3 turns and on the 4th will play the Twilight Drake. This will give the Warlock a 4/8 or 4/9 creature, depending on whether he went 1st or 2nd and has the coin or not, on his 4th turn. This creature will easily be able to deal with most any 1-3 cost creatures that the opponent has laid down in the previous turns.
One of the preferably two creatures in your deck that cost 2 mana to play, the Ancient Watcher is a 2 cost creature with 4 attack and 5 health with the pesky drawback of not being able to attack. This card has great synergy with cards like Shadowflame, Sunfury Protector, Defender of Argus, and any creature that can silence the watcher making it able to attack.
The Sunfury Protector is a 2 cost 2/3 creature that when played gives creatures adjacent to it the Taunt ability. This card is paired wonderfully with the Ancient Watcher because it forces the opponent to have to deal with it while before they could have just ignored it. This card has annoyed me to no end as it would turn a slightly bad situation into a cripplingly bad situation for me when played against me.
Perhaps the most important card in the Warlock deck this card is capable of clearing the entire enemy board for a small price. This 4 cost card destroys one of your friendly minions and deals its attack damage to every enemy minion on the board. Ancient Watcher becomes a cheap way to deal a crushing 4 damage to all enemy minions. Sylvanas Windrunner pairs extremely well with Shadowflame as her deathrattle will let her take control of an enemy creature that happens to survive a 5 damage nuke. I cannot stress enough how important this card is because unless you run a Hellfire this will be your only way to clear out a bunch of enemy creatures at once. Power Overwhelming is a perfect combo if the enemy has beefy creatures since the creature will die to Shadowflame anyway you won't bother with Power Overwhelming killing it and you could even get a hit in before you cleared.
Defender of Argus
The Defender of Argus costs 2 more than the Sunfury Protector with the same effect except the Defender of Argus also gives +1/+1 to the adjacent creatures and that may just be enough to clear the enemies board while keeping your creatures alive with one health.
As you continue to Lifetap away and lose more health Siphon Soul is a great way to get some of that back while killing a big creature in the process. This 6 cost card instantly destroys the targeted minion and returns 3 health to your hero. An invaluable card to give you some healing that you desperately need.
However being low on health is a good thing with the Molten Giant card. This 20 cost card is an 8/8 whose cost goes down for every point of health your hero is missing. That means that when you get down to 10 health this 8/8 costs 0 mana to play. You can pair this with Shadowflame and deal 8 damage to all enemy minions on the board. You might also want to play your Molten Giant or ideally both of them and then fit a Sunfury Protector or Defender of Argus for an easy double 8/8 taunt. The other giant you want is the Mountain Giant this is a 12 cost 8/8 whose cost goes down for each card you have in your own hand. If you shamelessly Lifetap and hold onto your cards you could ideally get this creature out on turn 5.
Antique Healbot is another way to get some of your health back while also getting your own creature on the board. This 5 cost 3/3 is extremely good, even a bit overpowered, as when you play it you receive a whopping 8 health back to your hero. Again this is invaluable as your constant Lifetapping will put you dangerously close to death.
Darkbombs don't forget your Darkbombs. This card costs 2 and deals 3 damage to either minion or creature, this is great for keeping the board under control until you can get to the late game or it can give you just enough to finish off the enemy hero. These are the primary cards you need for successful Handlock and you can add variant cards as you desire.