The Dark Portal is key card in the deck and goal is to make your high cost minions cheaper and then swing board in your benefit. Demonic studies makes your Tickatus and Jaraxxus even cheaper. Twisted Knowledge could give your extra copy of The Dark Portal and any other useful card for the matchup.
Any early clear should work vs aggro.
Almost same as usual mulligan but dark skies could come handy in this matchup.
Combo decks are also one of the target decks with this deck, so the mulligan is the same as in section General.