This deck combines the aggressive Eldrazi with the additional combo win. In case you can't win by smashing, stall the game so you can combo out a win using Eldrazi Displacer.
PLAYING THE DECK:
As with all Eldrazi decks, you have access to 4 Eldrazi Mimic cards. I've removed the Endless Ones, as it's a liability if your opponent is also playing Eldrazi Displacer, and replaced them with Training Grounds and/or Altar of the Brood.
You still can play an aggro race with Mimics on turn 1,
And Thought-Knot Seer on turn 2,
And then Reality Smasher on Turn 3!
While you have 3 Dismember cards in the deck, there is no Urborg in the deck. However you do have 4 Path to Exile cards. Dismember is good in the mirror when your opponent plays Reality Smasher or Drowner of Hope with their own Mimic's.
COMBOS:
Altar of the Brood +
+ Eldrazi Skyspawner = Mill for 2
+ Drowner of Hope = Mill for 3
Eldrazi Mimic + Reality Smasher OR Drowner of Hope = Turn mimic into a 5/5 beater
This also works by flickering either of the latter using Eldrazi Displacer, although you lose one of your attackers.
Training Grounds + Eldrazi Displacer = <> Mana to blink (and tap) a creature
Training Grounds + Eldrazi Displacer + Eldrazi Skyspawner = Always have two blockers
Training Grounds + Eldrazi Displacer + Drowner of Hope = Infinite mana and/or Infinite 1/1 Eldrazi Scion creatures
Training Grounds + Eldrazi Displacer + Drowner of Hope + Altar of the Brood = Mill your opponent by generating an infinite number of creatures
Training Grounds + Training Grounds + Spawnsire of Ulamog = Activate first ability for (1) and then generate infinite mana and/or 0/1 Eldrazi Spwan creatures
(sorry, these will be 0/1s, so you can't swing in)
(Infinite Mana) + Spawnsire of Ulamog = Activate the (20) ability and cast all Eldrazi spells (not just colorless, so you could have changelings there) in your sideboard (or what you sideboarded out after game 1), including Emrakul and Ulamog.
Nice thing is you can even tutor for Spawnsire when needed.
(Infinite Mana) + Thought-Knot Seer = Infinite exile effects and force your opponent to draw infinite cards.
This can backfire though, as they can respond to each trigger (and they will have a new card each time).
This however gets around Emrakul being milled, as you can flicker Thought-Knot Seer to force your opponent to draw when Emrakul's graveyard trigger occurs (if their deck is empty).
Unfortunately, all the infinite mana solutions here require Training Grounds, and this deck should run three to four in the main. You can still use Eldrazi Displacer to generate multiple tokens without it (and with Altar of the Brood, meaning milling your opponent), but it will be much slower.
MATH
When flickering Drowner of Hope using the tokens it generates ---
- Normally you will need 3 tokens to flicker, which generates 2 tokens.
If you have 6 tokens, you can flicker 5 times. This generates 15 enter the battlefield effects.
- With Training Grounds in play, you generate 2 tokens per flicker, meaning the number of times you flicker with a scion token, you will end up with 1 + (times you flickered) number of tokens
NOTE: Normally you do not sideboard in Emrakul or Ulamog as they can be fetched with Spawnsire of Ulamog, but it's perfectly fine to replace Spawnsire with Ulamog, as they cost the same mana.
PROBLEM CARDS:
Worship --
Consider winning with the mill combo instead of aggro. However in the sideboard you do have Emrakul and Ulamog that can be played from the main deck via the singleton Spawnsire of Ulamog.
In the sideboard, you do also have Disenchant and Echoing Truth to deal with this problem enchantment. Stubborn Denial is also another excellent option.
Spellskite --
With this out with your opponent, your flicker targets are just targeting Spellskite. You cannot win with mill, unless you happen to have enough mana to force their life total to zero.
In the sideboard, you can use Disenchant, Echoing Truth, or Linvala
Torpor Orb --
You can't generate Scion tokens with Drowner of Hope and/or Skyspawner, but you still can generate Spawn tokens with Spawnsire of Ulamog. Also turns off your Mimics.
Sideboard in Disenchant, Echoing Truth, and Stubborn Denial.
Chalice of the Void --
This turns off your mill strategy.
Sideboard in Disenchant, Echoing Truth, and Stubborn Denial.
Ensnaring Bridge --
This turns off your aggro strategy.
Sideboard in Disenchant, Echoing Truth, and Stubborn Denial
Affinity --
Sideboard in Stony Silence, Disenchants, and Stubborn Denials. You may also want to sideboard in Echoing Truth. Ratchet Bomb would be a good alternate sideboard consideration here.
Blood Moon --
I'm seeing these in the main now. We don't have any way to stop it main board, so make sure to fetch for basics, and you may need to path your own creature to get a Wastes.
Sideboard in Disenchant, Stubborn Denial, and Echoing Truth.
Leyline of Sanctity --
This isn't a show stopper, as it only affects Thought-Knot Seer (yes, Altar of the Brood says "each opponent").
Sideboard in Disenchant and Echoing Truth.