ALL the plagues

You know that part in the old testament when Moses calls down the 10 plagues? This deck confidently says "Hold my beer, Moses," then proceeds to unleash devastation of greater-than-biblical proportions. 

First, we use every card that can shuffle plagues into your opponent's deck.

Then, we run as many discover effects as possible (Necrotic Mortician, Nerubian Vizier, School Teacher, etc.) so we can find MORE cards to shuffle MORE plagues into your opponent's deck.

Finally, we force the opponent to draw cards until they find ALL the plagues. For this we have both Frozen Over and Selfish Shellfish.

Death Growl might be the best card in the deck, as it synergizes fantastically with Distressed Kvaldir, but can also be used on Chillfallen Baron or Selfish Shellfish in a pinch.

The Primus doesn't do anything specific for us, but is just an amazing card that fits in just about every Death Knight deck. Plus, we don't really have any healing (besides those delicious Blood Plagues), so this Titan can help in that area.

Chained Guardian is a baller. I'd probably run 2 of him if I had them. If you've played Helya, the plagues getting reshuffled into the opponent's deck discount this big boi even more.

Steamcleaner: Yes, we hate this card. BUT do not concede when he shows up. If you have the ability to shuffle MORE plagues later, you can still win.