This deck is a Warlock constructed to beat the Lich King (KoFT Adventure) - built with a Free to Play account and based on Tommy J's featured deck here https://www.youtube.com/watch?v=M05BGqzKNLU
The idea behind this deck (as with many F2P decks for this adventure) is to defeat the Lich King before his turn 7 when he drops Frostmourne. And like many of the F2P decks for this adventure they are heavily reliant on RNG.
The key cards in this particular deck are Knife Juggler and Vicious Fledgling. Ideally you have a card to drop on turn 1, Knife Juggler turn 2, and Vicious Fledgling turn 3. All other cards here are to aid / defend these cards. Dropping Fledgling on turn 4 is possible but you would like to have good board presence already and be very lucky with your adapt options and favorable card draw on the Lich King's side.
The key adapts for Fledgling are Windfury and Can't be targeted w/ spells so Lich King can't nerf (although be aware once you have this it applies to you to and you can only buff it via other minions; Raid Leader, Shattered Sun Cleric, etc).
I'll admit I had to craft both Fledglings for this deck - at a cost of 200 dust altogether since Blizzard brought the cost down once KnC was released.
The other card of note I have included here is Forbidden Ritual which I added to make use of Knife Juggler but which I did not end up using in my winning playthrough and can likely be subbed in for another buff / taunt minion instead.