Hello!  I'm sure you've seen similar versions of this deck in the past.  Basically, you try to survive the early game and complete your quest.  Dollmaster Dorian and Fel Lord Betrug synergize well with Plot Twist and all the Deathrattle/reborn cards in the deck. 

The win con is Play Mecha'thun and a Plague of Flames after your deck is empty.  However, this costs 11 mana, so one of the cards needs to be reduced.   You can do this by playing Emperor Thaurissan with one of those cards in your hand (after you play the 2nd Plot Twist), or you can get lucky and draw a 0 cost combo piece with the post quest hero power - Tome of Origination.  If that doesn't happen, make sure to save your Galvanizer for the end (after you play both Plot Twists).  Then play Galvanizer to reduce Mecha'thun.  (Remember when you use Plot Twist, the card mana values reset!)

I'm playing at rank 7 right now.  I'm sure the deck can be optimized.  I'd keep most of the taunts, but you could cut Sylvanas Windrunner, Mechanical Whelp, and/or Cairne Bloodhoof for more early game cards.  Emperor Thaurissan and Dollmaster Dorian prob aren't needed either, but these cards are not bad and very fun imo.

Curse of Weakness is Awesome!!!  Very good to slow down aggro decks.

Let me know if you have any suggestions.  I'll keep trying and post updates if this helps me climb.  Good Luck!

 UPDATE - 11-10-19

- Cairne Bloodhoof, - Mechanical Whelp, - Sylvanas Windrunner, +2 Questing Explorers, + Tar Creeper + Voidwalker (sorry, not meant to be a wild deck - lol)

So I took out some 6-drops to make a better early game.  I was torn between removing Emperor Thaurissan or Sylvanas Windrunner (or both).  This is what I'm trying for now.