Eldrazi is a tribe that need little introduction. They have been a powerhouse in every format since the infamous Eldrazi winter, but are especially potent in Legacy due to the sheer number of Sol Lands available in the format. Most Eldrazi decks are colourless and rely on explosive starts and Chalice of the Void to lock their opponents out of the game. They "go bigger" than other fair strategies, but without Chalice of the Void or a turn two Thought-Knot Seer, can be a little weak to combo. Many lists therefore opt to run Thorn of Amethyst in the sideboard.
This deck is a little different.
There are a couple of reasons to combine the Eldrazi package with Death and Taxes. The first is Thalia, Guardian of Thraben. She has been a thorn in the side (see what I did there?) of both Delver and combo players since her printing in Dark Ascension, and is a perfect replacement for Thorn of Amethyst...except we get to run a full set in the main deck. The second is Eldrazi Displacer, which is hands down the best card in this list, and the most powerful tool we have to grind our opponents into dust. Additionally, we get to keep the broken start of turn one "Chalice for one, GG?"
Let me start by showing you the list.
4 Thalia, Guardian of Thraben
2 Thalia, Heretic Cathar
2 Recruiter of the Guard
2 Stoneforge Mystic
2 Containment Priest
2 Palace Jailer
4 Eldrazi Displacer
4 Thought-Knot Seer
3 Reality Smasher
4 Chalice of the Void
4 Mox Diamond
1 Umezawa's Jitte
4 Ancient Tomb
4 Eldrazi Temple
2 City of Traitors
4 Cavern of Souls
4 Swords to Plowshares
3 Rest in Peace
2 Ethersworn Canonist
2 Phyrexian Revoker
1 Sword of Feast and Famine
With Containment Priest in play, you can permanently exile any creature your opponent controls for the low cost of three mana. Gone. Poof. Forever. This combo allows us to grind superbly and deal with otherwise obnoxious threats, like Baleful Strix. It certainly helps that Containment Priest is a solid creature in Legacy regardless, beating up on Dredge, Reanimator, Sneak and Show, Green Sun's Zenith, and much more.
Moreover, Containment Priest can be tutored with Recruiter of the Guard, which I think is an excellent addition. Recruiter can be blinked by Eldrazi Displacer until you have a Containment Priest on the field, providing great value and a small toolbox selection. Tutoring up the removal/card advantage engine of Palace Jailer is nice, too.
Speaking of which, I was seriously impressed with Palace Jailer in testing. It's obviously amazing vs Show and Tell decks, but definitely pulls its weight in match ups which our opponent's deck has few creatures, too. It provides much-needed removal, with the serious bonus of having card draw attached, which is especially welcome in an archetype that traditionally lacks any form of card advantage or a way to filter its draws. The nice thing about Palace Jailer is that our opponent only becomes the monarch when we are dealt combat damage, not when Palace Jailer leaves play. This makes Jailer an excellent creature to blink with Displacer.
Stoneforge Mystic is, surprisingly, my least favourite card in the deck, but a necessary evil. It is slow, granted, but Jitte and Batterskull are powerful cards and having access to them is nice. You can also get tricky and activate Stoneforge Mystic's ability and blink it with Displacer in response, tutoring for the second equipment and putting it directly into play. Sneaky.
The last piece of the puzzle is Thought-Knot Seer, which is a no-brainer with so many Sol Lands.
The last thing I'll say about Eldrazi Displacer is that its 's just a good creature, holding down the fort vs Emrakul, Marit Lage, Gurmag Angler, and other such nonsense. It even flips Insectile Aberration back into Delver of Secrets and can also be played as early as turn one. Are you sold yet?
If Eldrazi Displacer isn't enough to sell you on the white "splash," the taxes package of Thalia, Guardian of Thraben and Thalia, Heretic Cathar might help. Both are extremely powerful turn one plays, and buy you precious time vs a myriad of decks. A turn one Thalia, Heretic Cathar on the play can be lights out vs an opponent who kept a fetch-heavy hand (especially if they play one of the numerous decks with greedy manabases that are rampant in Legacy these days), and Thalia, Guardian of Thraben is as good as ever vs both combo decks and decks that want to play the most efficient spells in the format (looking at you, Delver). They help to buy us time to deploy our more powerful threats or set up our long game using Eldrazi Displacer. Also, we run the full set of Wasteland to further press the advantage these creatures can provide in the early-mid game.
Looking at the rest of our mana, Cavern of Souls is huge game against any deck that runs counter spells. With only two real choices to name, Caverns is very powerful in the deck and an obvious inclusion. We also get to run ten Sol Lands (although Eldrazi Temple can't cast a turn one Chalice of the Void), which help to power out both our Eldrazi and all the 2W threats we run. Karakas is as great here as it is in Death and Taxes, providing utility with both Thalias and giving us more game against Marit Lage, Griselbrand, and Emrakul decks. Finally, having access to basics is nice, especially in the face of Blood Moon, which tends to get boarded in against Eldrazi. If you see a ton of Blood Moon in your meta, trim the number of Karakas and add another basic Plains. Our land count may seem high, but it's a necessity when you run Mox Diamond, which is an important piece of this deck, allowing us to cast Thalias, Displacer, Stoneforge Mystic, and Chalice of the Void on turn one.
Having access to white also gives us some great sideboard options. Swords to Plowshares is the best removal spell in the game, and is often sided in against other Chalice of the Void decks that run creatures (cough, colourless Eldrazi, cough). Rest in Peace is incredibly powerful in the right match ups, and was chosen over faster graveyard hate such as Surgical Extraction because it's higher-impact and can be played on turn one with Mox Diamond. Also, the BR Reanimator decks seem to have disappeared somewhat lately. Ethersworn Canonist and Phyrexian Revoker are both great creatures from traditional Death and Taxes lists that can be tutored with Recruiter of the Guard or played on turn one. No explanation necessary there. Armageddon is a bit of a strange choice, but helps vs Lands and other fair decks that want to go bigger than you. Finally, I added a Sword of Feast and Famine because there are a lot of decks running Baleful Strix at the moment in my meta, and they have started to put Glissa, the Traitor in their sideboards to re-buy Strix (also a first strike death touch creature is no slouch vs Eldrazi). Untapping all our lands is also an incredible effect in a deck as mana-hungry as this one.
Overall, the deck is a blast to play and feels very powerful. It's capable of fast starts, unbeatable turn one plays (matchup dependant, of course), and has a crazy ability to grind out games thanks to Eldrazi Displacer. Give it a whirl!