Mulligans
Brann Bronzebeard is not used becuase buffing Twilight Drake more is not needed, and Dr. Boom summoning more boom bots can actually have negative synergy with N'Zoth, The Corruptor. Twisting Nether also has bad synergy with N'Zoth, The Corruptor which is why it is not run. Kel'Thuzad with Faceless Manipulator can be a win condition, a dream condition can be: Kel'Thuzad stays on board from last turn (this is quite often, your opponent probably used all their removal) and then with Emperor Thaurissan you can play a Mountain Giant, then Faceless Manipulator the Kel'Thuzad, and then Shadowflame the Mountain Giant, which clears the board, and you have 2 Kel'Thuzads and 2 Mountain Giants. Of course this doesn’t always happen, but you can very often gain massive value from him putting a Chillmaw or Sludge Belcher between it, which can stop the combos of tempo mage with flamewakers. This also buffs your N'Zoth, The Corruptor value, making Kel'Thuzad a win condition, a card that halts your opponents value plays, and makes N'Zoth, The Corruptor way better. Chillmaw is super good for N'Zoth, The Corruptor, and Faceless Manipulator, plus it is a big taunt when resummoned by Kel'Thuzad.