I have been having a lot of fun and success with this Dragon Priest build.
The last card in the deck is Nefarian.
Brann Bronzebeard, Museum Curator, and Entomb have really helped extend the reach of the deck. Dragon Priest was decent enough before League of Explorers, but the addition of those cards gave it just what it needed to become versatile enough to match up well against a wide variety of competition. Brann's best combo is with Curator. But getting the extra attack on your Wyrmrest Agent or Twilight Guardians is certainly welcome. He also goes well with Azure Drake. Blackwing Corruptor becomes a Fireball. It's unlikely to get him off with Nefarian but I have done it once and it was extremely powerful.
Starting with Twilight Whelp is important. If you have one of those in your starting hand, I would mulligan everything else to look for a dragon. The exception is if you get a Wyrmrest Agent - I would play that on 2 and save the Whelp for later.
The deck is very strong against aggro if you can get your Whelps and taunts out early. With the high health of your minions, they will have a tough time winning the value game if they're trying for board control i.e. Zoo. Against Hunter, Wyrmrest Agent is game winning. Their best shot is to hit it with a Juggle and sac a Knife Juggler in to it. Aside from that they'll just never get through to you. Draw an Abomination form Curator and you'll be clearing a lot of their board.
Against control, Curator and Entomb are the big winners. Throw down a Brann and Curator and suddenly you've got the late game to contend with these guys. Some nice pulls have been Chillmaw, Carine, Sylvanas, Toshley, Sludge Belcher, Piloted Sky Golem to name a few. If you get two of those, plus Entomb their own Sylvanas they just have too tough of a time out-threatening you.
You could certainly play around with spots like Thoughtsteal, Piloted Shredder, or maybe Dark Cultist. I was running 1 Sludge Belcher but swapped it out for a Loatheb since you've got enough taunt int he deck and if you're waiting for Belcher to stop aggro then you've probably already lost anyway.