Eldrazi has taken over Legacy, and since Legacy is a format where news develops very slowly, it’s time to look at how you should fight the new deck.
Let’s take a look at your enemy first:
The deck relies a lot on Chalice of the Void and you can have multiple game wins just by casting a Chalice on 1 on turn one—a plethora of decks concede on the spot if that resolves.
The deck has a ton of lands—it needs those because of Wasteland, which hurts the deck since it needs its Sol lands to work flawlessly.
Eldrazi is a colorless deck, so you can’t play Force of Will, which is a big issue in a format like Legacy where there are so many combos that can kill you on turn 1. But those decks are the ones hurt most by a Chalice on 1 or a Thorn of Amethyst. Hence, in order to beat Eldrazi with those decks (ANT, Reanimator), you have to win the die roll and have a very explosive hand.
Let’s start with which cards/decks are ideal to face Eldrazi.
This is a reason why Eldrazi in Legacy isn’t as broken as it is in Modern—Wasteland plays a huge role in holding back the Eldrazi, but it has to be paired with pressure. You can’t just Wasteland your opponent and hope he doesn’t draw anymore lands—they play 25 and 3 Simian Spirit Guides for a reason.
Delver decks are the best at doing this, since a turn-1 Delver of Secrets is the best way to pressure them. That’s why I think that Grixis Delver is well positioned at the moment—even if it has a negative matchup against Miracles, it does have a good matchup versus combo and this new threat.
Daze is another huge reason why I think the matchup is favorable. It shuts down the turn-2 Thought-Knot Seer, which is crucial for them and the reason why the deck is great. They can play around it, but you’ll gain tempo, which is very often the key for Delver decks to prevail.
I’m not sure Death and Taxes is well equipped to defeat Eldrazi. On one hand, they have Wasteland and Rishadan Port. On the other hand, they don’t pressure you fast enough and Mother of Runes is only good against 3 cards in your opponent’s 75.
Wasteland recursion is definitely the best way to do it and Lands and Aggro Loam can easily do that thanks to Life from the Loam. Overall, Lands is the best deck to beat Eldrazi. Other than Wasteland, it has Maze of Ith, which is phenomenal against Reality Smasher, and the Thespian’s Stage + Dark Depths combo comes fast and can’t be answered from the Eldrazi side (just a pair of Karakas).
2. Don’t play a deck that folds to Chalice of the Void on 1
I know this could be tough, and as much as I love ANT, this is not the right moment to play it.
There is too much hype around Eldrazi and the matchup is almost unbeatable since they have 8 cards that kill you game 1 and they usually board in even more annoying artifacts: Thorn of Amethyst, Sphere of Resistance, Phyrexian Revoker, etc.
You could argue that Delver decks die to Chalice of the Void on 1 as well, but that doesn’t really hold up. They definitely do if the Chalice resolves on turn 1/game 1 on the play, but otherwise, Delver decks are equipped to fight it with counters or by casting other cards.
3. Play a very explosive deck that can kill them on turns 1 and 2
I added this point to the list even if it could be a trap. Fast and explosive decks are usually weak to Chalice of the Void, Thorn of Amethyst, and Sphere of Resistance, which are cards played in the main deck and sideboard by Eldrazi.
Belcher and All-Spells can easily win game 1 when not facing a Force of Will, but that’s not Magic and I can’t recommend a deck that’s so unfun for you and your opponent.
Chalice of the Void is definitely annoying but you can easily win with Invigorate and Become Immense. You also have Viridian Corrupter and Green Sun’s Zenith to blow it up if needed. Eldrazi is a deck with very little interaction and that’s important when playing against Infect.
At the moment, Eldrazi is causing a lot of angst. I suggest that everyone take it easy—they were a mistake in Modern, that mistake will be fixed, and they will continue on in Standard and Legacy along with other decks that are more broken and more annoying to play against (Miracles, anyone?).