I’ll admit, it took me a second read to realize how good this card is. For starters, the ability is much better than Tidehollow Sculler’s. Rather than get their best card back, they get a random card off the top, which has a decent chance of being a brick (or at least worse that the best card in their hand).

Thought-Knot’s ability is better than Clique’s, too, because if you don’t kill the Thought-Knot, you don’t get a card back. It’s like they took the best parts of Vendilion Clique and Tidehollow Sculler, slapped it on a 4/4 beefcake, and gave it the Eldrazi tribal synergies.

Of course, part of Vendilion Clique’s appeal is that it has flash, and you can do neat things like play it during your opponent’s draw step, at their end of turn, or even in response to something big like a Show and Tell or a Stoneforge Mystic activation. Thought-Knot doesn’t do any of that unless you’re messing around with Aether Vial, and even then, 4 is a high spot on a Vial curve.

Pros

• Ability is better than Clique’s or Sculler’s
• Immune to Bolt and Abrupt Decay
• Eldrazi tribe synergies

Cons

• Colorless cost requirement
• Doesn’t have flash like Clique

All of these things point toward Thought-Knot Seer becoming an Eternal staple, but in vastly different decks than Vendilion Clique.

The most likely home is in the Eldrazi tribal deck that has been surging through Modern. There, it’ll add another layer of disruption, exile cards for Blight Herder and Wasteland Strangler, and come down as early as turn 2 off of a pair of tribal lands.

Here’s a decent starting place:

Thought-Knot Eldrazi Black

As far as the threat count goes, it’s possible that Matter Reshaper shouldn’t be in there. Most of the time, it’ll just be sweet value when it dies, but sometimes it’ll ramp you. I think it’s worth testing, but could be worse than another Scrabbling Claws and a main-deck Ulamog.

If you examine the mana base, you can see the reasoning behind Talismans over Mind Stones, as the Talismans help you get to 12 black and 13 colorless sources. Another way to reach the right count is to replace some of the utility colorless lands with lands that produce both black and colorless mana, like Llanowar Wastes.

There are two reasons to up the Cavern of Souls count. For starters, Reality Smasher is a stupidly hard card to deal with, and making it consistently uncounterable only adds to that. In the most busted draws, you don’t want to have to spend a turn tutoring for Cavern, you want to draw it naturally. I could see going up to 3, especially if you’re entertaining a light splash for Drowner of Hope, which is excellent in a lot of matchups and helps clear random Tarmogoyfs and Gurmag Anglers out of the way for Reality Smasher.

The other thing that Cavern does is up your colorless count for the new Eldrazi cards, which is pretty important because you’re running more of them than black cards now. Fortunately, you want to be tutoring for Eldrazi Temple with the Expedition Maps anyway, so you should usually have colorless when you need it.

Note that if you use Cavern to fulfill a colorless requirement, your creature will be very counterable! It’s a non-intuitive little nonbo with the Eldrazi tribe, since usually the ability on Cavern is also fixing your mana.

Of course, there is a format with even more explosive mana available, where you could easily fill a deck with quality colorless lands.

I’m talking about Legacy.

Legacy Eldrazi

My buddy Mike Meier gave me the idea for Legacy Eldrazi and I ran with it. Mono-Brown is always borderline good enough, so any new technology has a lot of potential.

This list has a few advantages over current builds of MUD. For starters, you have both the Sol lands and the Eldrazi lands for acceleration, which increases redundancy. And you aren’t relying on vulnerable cards like Metalworker. The Eldrazi creatures fill in holes in the curve nicely, and Thought-Knot Seer is a type of disruption that MUD hasn’t had access to before.

I don’t think Matter Reshaper is amazing, and it might turn out to be worse than Lodestone Golem or Endless One, but I think it’s worth testing. It fits the curve, carries equipment, and has potential for value. Turn-1 Sol land plus Mox Diamond into Matter Reshaper sets up a turn-2 Jitte plus equip, and if the opponent Bolts it, there’s a large chance it ramps you or finds something sweet.

Warping Wail is another card I’m not sure about, but it seems fine as a sideboard card for Elves and Show and Tell decks.

Another way to build the deck is to get closer to the Modern version. With a few tweaks to the mana, you could maindeck Leyline of the Void and run Blight Herder. Or you could drop the Chalice plan and run Relic. Yet another way is to keep Chalice and add white for Rest in Peace, which would also give access to Stoneforge Mystic.