Magic: The Gathering Cube design has exploded in creativity over the last few years, and few projects embody that innovation better than the Companion Cube, designed by Greg "Dinrova Horror." In this article, we unpack Greg's design philosophy behind the Companion Cube, as well as his broader views on Cube design and event organizing.

Who Is Greg "Dinrova Horror"?

If you live on the east coast of the United States, Greg might be most well known for the Vertex Cube Series, a semi-annual 128-person Cube event that takes place in Pennsylvania. Though if you ask people in a few months Greg might become better known as a co-founder of the much anticipated Shoe Box Convention, a three day Magic event in Minnesota, but more on that later. Instead let's jump in and discuss the skills and insights that make Greg such a prolific Cube Designer.

What Is the Companion Cube?

Remember Ikoria, the set with a mechanic so broken that Wizards of the Coast had to emergency errata an entire cycle of cards? I don't. I was taking a break from retail Magic at the time and missed the whole debacle, but Greg remembers and asked himself two very interesting questions as a result. What if an entire Cube was based around the Companion mechanic, and what if it was actually fun?

The Companion Cube is built around a radical but elegant rules change.

• You can companion any card in your pool
• It follows the original companion rules (no extra three-mana tax)
• Your companion can be anything. A Creature, Land, Enchantment, Artifact, etc.

This is how Greg describes it.

• "A free Demonic Tutor as an eighth card in your hand"
• Or "a commander you can only cast once, with no color identity restrictions"

The emotional hook mirrors Commander. At the start of each match, both players reveal the single card their entire deck is built around. That reveal, be it Wilderness Reclamation, Up the Beanstalk, Aether Vial, or even Plaza of Heroes creates a strong sense of identity and narrative for every deck.

Designer-Inspired Origins

Companion Cube's genesis traces back to Greg's post-COVID return to large events:

• MagicCon in 2023 reintroduced him to the modern Cube scene.
• He drafted several "designer Cubes", including the Cascade Cube and the Devoid Cube.
• Cascade Cube in particular, with its Maelstrom Nexus emblem and zero-drop build-arounds, deeply influenced his thinking

Seeing how powerful and emotional it was to discover what someone had built their deck around mid-game gave Greg the seed for the Companion rules twist.

Why Companion Cube Feels So Different

The concept for the Companion Cube is already so unique, but what makes it really stand out in the world of Cube design?

Highlighting Constructed Staples That Don't Normally Work in Cube

One of the main design goals is to "rescue" cards that are iconic in Constructed formats, but too inconsistent for most singleton draft environments. Cards like Aether Vial, Amulet of Vigor, Hogaak, Arisen Necropolis reach their full potential in this Cube.

This approach leans heavily on Constructed history and nostalgia. Greg intentionally favors cards that have a real tournament pedigree, spark emotional resonance, and encourage players to say, "I've always loved this card, what if I built my whole deck around it?"

Hundreds of Viable Archetypes

With 384 cards and the ability to companion almost any of them, Companion Cube offers an astonishing amount of replayability.

• Greg estimates 300-350 cards are "totally reasonable" companions
• Many cards like Currency Converter function as one-card archetypes.
• Even within a narrow lane like Red-White aggro, your deck changes dramatically depending on whether you companion Arena of Glory or Yoshimaru, Ever Faithful

This pushes drafters to explore new builds and synergies every time, while still feeling structured and intentional.

Companion Lands: Subtle but Deep Design

Lands play an unusually important role in Companion Cube because lands can be companions.

Early feedback to Greg's rules concept was, "Why wouldn't you just companion a dual land and play 10-land aggro every time?" While land companions like Plaza of Heroes can be extremely strong, real data from events like CubeCon suggests they're not overwhelmingly dominant. Instead, they're powerful signposts for archetypes (e.g., 5-color aggro, 5-color legends control), and an interesting option in the broader meta.

Greg makes deliberate choices with the lands he includes, like Ghost Quarter over Wasteland. Where one is so effective that it invalidates other decks, the other interacts with lands in a way that lets opponents still play the game. The subtle choice of including Ghost Quarter enables fascinating gameplay choices like targeting your own land and casting Brought Back as a form of ramp. Or my classic, "soft" Strip Mine loops with Exploration and Ramunap Excavator.

Greg's Broader Design Wisdom

The concept of prioritizing interesting play patterns rather than maximizing raw efficiency is just one of the most important lessons Greg would impart on new and experienced Cube designers. Moving away from the Companion Cube and toward broader design wisdom, Greg had a few things to say.

16-Card Packs Over 15

One of Greg's spiciest but compelling "hot takes" is that more Cubes should support 16 card packs instead of 15. Why?

• In an 8-player draft with three 16-card packs, every pack wheels twice
• There's no "dead" 7-card pack that doesn't come back around
• With 384 cards, you still see the entire Cube
• The structure is cleaner and more symmetrical

More broadly, Greg's point is, "Pick a pack size that makes sense for your Cube," rather than blindly copying retail norms that trace back to baseball card pack sizes, not game design.

It's wisdom that I personally took to heart when I updated Everything Everywhere. This strange Cube asks players to play every card they draft. Rather than using the usual three packs of 15 and forcing players to have 45 card decks, I experimented with two packs of 20, and four packs of 10. Over many drafts I found different, compelling reasons why each of them worked and both felt much better than the alternative.

Shoebox: The Event of the Year

To close the interview, let me take a moment to highlight Shoebox in more detail. Located in St. Paul Minnesota (a central travel hub) on March 13-15 2026, hundreds of players will gather to celebrate community and their favorite fringe formats. The event features a 3-day main event centered around Cube but also boasts dozens of incredible side events like cEDH, Team Limited, and Pauper.

In Greg's own words, "The focus of Shoebox is about supporting our players and community, not about maximizing sales." They'll have community artists, a Dandan tournament, they'll even have a carnival full of fun mini-games and prizes. If you needed a reason to get out of your house and have fun, this is it!

Lastly, if you needed any more convincing that the Cube community is a special one, I'd like to remind readers of the Cube Fellowship Program. If you're interested in attending Shoebox or any other Cube event but can't go for financial reasons, the Cube Fellowship Program can help remove those barriers. The fine folks over at Lucky Paper believe that, "Cube events thrive when they are filled with players who are positive, welcoming, and community minded." Apply to be a Fellow Today and don't miss out on this awesome event.