This is a first version of my Gothic updated Deathspeaker Control decklist. Note that my previous list was Earth/Air/Fire while with Gothic I will play just 2 elements (Earth/Air) for now. All new card choices with explanations you will find further below in the primer (to be added).
General strategy:
This deck tries to be a recent version of Deathspeaker control and an alternative to the dominant Archimago control decks. The main goal is to survive till the midgame with small utility creatures blocking and strategically using point and mass removal. After that point you focus on heavy card draw until you can finish off your opponent with heavier creatures or Craterize. With the fast mana of the Cores you can ramp out your spells faster. Place Lady Iseult in safe distance behind your other minions to maximally exploit her ability to return wizards and other minions to your hand when they die. Gnome Hollows, Perilous Bridge and Pebbled Paths must be placed strategically to prevent your opponent from reaching you. If you want to setup a nice Boneyard turn, make sure to eliminate potential threats from your opponent's graveyard with your Deathspeaker's ability in advance. Feel free to ask your questions here if there are any.
Earth/Air vs. Earth/Air/Fire comparison:
While the inclusion of the new dual threshhold lands allows you to play the three element version of this deck greedier with 3x threshhold cards of all 3 colors basically there are 2 huge advantages that the 2 element version offers as well. The main advantage that lists with 1 or 2 elements in general have are the better utility sites. As a control deck placing defensive sites strategically on the board to prevent creatures from rushing you is a key component to arrive in the late game and launch one of your finishers. Besides the obvious ones (Gnome Hollows, Perilous Bridge and Pebbled Paths) you also can use the advantages of Cloud City, Merlin's Tower, Mount Ussar, The Manor and Wormelow Tump. Most of those would have to be replaced with dual lands for threshhold consistency in a 3 element version. The second advantage that the 2 element version offers with Gothic is the bigger card pool and also through the new dual lands the possibility to play 3x threshhold or even 4x threshhold cards way easier. Both of these factors help you to have an average card quality almost as high as with 3 elements which wasn't the case before Gothic.