As expected, the deck has seen some more tinkering and the list has been updated to the one played by Zalae on stream a few days ago, and he made an official youtube video here: Know Your Enemy: Cube Lock w/ Zalae
Mountain Giants have been teched it, while Twisting nether is out.
This list was played extensively by Zalae on stream on 16/17 Dec 2017 at high legend (you can check the Twitch VOD for that day Zalae's Cubelock Twitch VOD) , refining it on previous lists by Thijs and other players.
New archetype and pretty fun deck, it probably will see a lot of refinement in the following weeks, since it is potentially tier 1 in the new meta.
Even during the stream Zalae made several changes to the list, taking out Umbra and N'Zoth.
It is possible that if it gets more popular people will start teching in weapon removal, since for the most part during the stream the Skull went pretty much unchecked.
It crushes aggro but it has even/weak matchups against Priest, since a well placed Psychic Scream risks filling your deck with tons of Voidwalkers.
The only Demons in the deck are Doomguards and Voidlords, which in the best case are never played directly, but either summoned from the hand (by the Skull of Man'ari) or recruited from the deck (by Possessed Lackeys).
The Carnivorous Cube + Dark Pact combo can be used both to spawn double Voidlords or double Doomguards, and Faceless Manipulator can be used to double the Cube itself or a high-value enemy minion, such as a Lich King or Ysera. Prince Taldaram works basically as a third (cheaper/worse) Faceless.
The rest of the deck is mostly removal (Twisting Nether, Hellfire, Defile), survival (Mistress of Mixtures), both (Amethyst Spellstone) or card draw (Kobold Librarian, Mortal Coil).
As such, it is a very flexible deck that presents often a lot of options, mirror matches are kind of a mindfuck (after a mirror with Zalae, Dog said he never want to play this deck again :)).