KeleControl

I've had a lot of fun with this deck, while having a pretty high winrate of 65%. Since I enjoy playing both aggro and control type decks, I tried making a merge of the two deck archetypes, ending up with this result.

There are a few cards that can be replaced. Kara Kazham! for example, is one of a few that can be swapped out for other cards such as Bane of Doom, Felfire Potion, Doom etc.

Mulligan guide:

Keep Flame Imp, Voidwalker , Malchezaar's Imp , or Prince Keleseth if you get them in your opening hand. Or else try to mulligan for them, since they all create a good body early on, and give you a decent tempo swing. Mortal Coil can be kept in your opener aswell, if you're facing Hunter, or in a mirror matchup.

Try getting your Mortal Coils and Soulfire drawn fairly quick, since you want your Spiteful Summoner to summon a 5+ cost minion to your board.

Arcane Tyrant might seem as a random addition, but it has great synergy with the deck, since you can empty the board with Twisting Nether, or Siphon Soul a big minion and play it out for free.

Bonemare and The Lich King are still great cards in the meta, and deserve a spot in the deck, I would not consider swapping out these cards, since they are pretty important in this deck.

The Darkness can be a risky pick/play, since you essentially take up a spot on your board for the rest of the game. Upside is that you can disrupt your opponents curve, and end up with a 20/20 to finish off the game.