Force your opponents to discard and sacrifice their creatures, then grab their creatures from their graveyard and send them back to them shambling and gnawing like a good creature should.
This deck really doesn't take off for at least 4 turns. The early game is very weak. I made it to play two headed giant with my friends and it works well.
Go for the Throat should be used to deal with any creatures that become bothersome Harsh Scrutiny will get some of their creatures in the graveyard and it allows you to scry. Dash Hopes has turned out to be a very effective early game counter, rarely will anyone take the 5 damage. Killing Wave is also a very effective board wipe early game because most people generally don't care about anything small early on.
Once you hit four mana you can drop either Undead Warchief, Liliana of the Dark Realms or
Korlash, Heir to Blackblade
. One of these should be in your hand by then. After that the game opens up, their are a few paths depending on what's in your hand.
If you get Liliana out you can ramp pretty quickly. Killing Wave and
Call to the Grave
are effective at filling up graveyards. Get a defense up either yours [Dread Slaver] or your opponents creatures Rise from the Grave. Then a Grimoire of the Dead is quickly sac'd by discarding lands. Then drop Endless Ranks of the Dead to gain plenty of tokens afterwards. This is the most ideal setting.
If it's either Warchief or Korlash, if you have a killing wave its good to use it before you play any creatures, then play off whatever you end up with.
Now a little on Grave Betrayal, the seven mana cost is actually not that bad in hindsight, it's not bad because your next turn you can pour seven or eight mana into Killing Wave and force your opponents to sac most of their creatures. Then they will be gloriously reincarnated on to your battlefield with +1/+1 counters.
In short, use what you have to make any actions against you have consequences. Someone attacks? Killing Wave. Someone has a beefy creature? Go for its Throat, then take it out of their graveyard and use it yourself!
Any feedback is greatly appreciated.