Rustwix's Phylactery

These cards are what make the combo happen. Rustwix needs to die first, then you can play Fiendish Circle (or a traded Wicked Shipment) into Tamsin, then play Phylactery which Tamsin copies, play the 0-cost Phylactery, and now you have an at least 5 minion board all with double deathrattles to earn you 30 Primes total. Not only that, but playing Vandarr makes EVERY prime in your deck go down to 3-5 mana. 

The rest of the deck is built for control until you can start pumping out your Primes, with Free Admission and Dark Portal helping you net the needed combo minions. As you'll be drawing nearly every turn (esp. once you play Dreadlich Tamsin), Mithril Rod is a must to help play more Primes more often. 

The deck will potentially be tweaked as more cards are revealed!