A different take on the Eldrazi Spawn Tokens - besides 2x Hand of Emrakul in the sideboard (included mainly for if you feel bad about not having any actual Eldrazi), the deck actually has no big Eldrazi dudes. Instead, it's all about the sacrifice! We'll be using all those Eldrazi Spawn Tokens to help fast-cast a bunch of spells, and then capitalizing on their sacrificing mechanic.
Nest Invader, Kozilek's Predator, and Dread Drone all help us get out a bunch of Spawn Tokens while still providing a reasonable creature base to more directly attack and defend. As a more passive token generator we've got the Awakening Zone. Add to these a Parallel Lives and suddenly we're cranking out quite a few Spawn Tokens in addition to our usual land base.
While these tokens can and absolutely should be used to help cast more spells (including ones to generate more tokens!), the trick is with their "Sacrifice to use" mechanic. Mortician Beetle simply ramps up with +1/+1 counters for each token you sacrifice, which is an awesome way to get up a beefy dude for only 1 Black, and Essence Warden will give us additional life for each one we create, but the big keys are Blood Artist and Skullclamp.
This is really where the main engine kicks in - Blood Artist not only gives us life for each token we use, but also deals direct damage to the opponent. If you couple that with a Skullclamp, suddenly you can actively give yourself life and take your opponent's away for each Spawn Token we create/destroy, not to mention the super card advantage each time we use Skullclamp. And all the while Mortician Beetle keeps growing. Throw in a Dictate of Erebos, and now each token you sacrifice also forces your opponent to sacrifice a creature as well!
If you're having trouble getting the right cards, Reaper of the Wilds can really help you dig with its scry ability. Growth Spasm can also help you get out some more tokens as well as a specific color land. And if your opponent has some super big dudes that you can't really deal with, there's always Tragic Slip or Blasting Station
As a last little bit of flavor there's also Damnable Pact, which you can not only use as a final play to destroy a near-dead opponent (who cares if they draw cards if they're dead?), but can also be used on yourself in a pinch if you're struggling to draw up the right cards (with Blood Artist and Essence Warden you should have plenty of life to spare).
