This is a cube designed around the sets that I feel had a few really good cards but were remarkably overshadowed in every other way: Kaldheim, Strixhaven and Theros Beyond Death. There are cards from other sets, but those are probably going to be the first on the chopping block.

When it comes to deckbuilding, you are allowed to substitute in snow basics for basic lands. Kaldheim did have the snow dual cycle and there are a few ways to make snow mana without using snow basics but the point of the cube is to show off some really neat sets and not being able to access parts of the deck because you never got passed a snow basic is just not part of the experience. There shouldn't be anything too absurdly broken, even the famous Valki, God of Lies is in the cube but shouldn't be an auto-win against every deck.

As for the archetypes:

: Foretell control. Leaning into Kaldheim for this, the foretell cards allow for cards like Alrund, God of the Cosmos to shine, while the Theros and Strixhaven cards in the color combo are mostly to support other archetypes, while still being strong in this combination.

: Aristocrats. Murdering your monsters for value sound like your kind of deck? The classic Silverquill deck finds itself a very nice home alongside Firja, Judge of Valor and Extus, Oriq Overlord to support an archetype that has long been associated with this combination.

: Boast. Lorehold has been known for turning their cards sideways for quite some time, and this cube is no different. Boast, a Kaldheim keyword, was designed mostly as a way to incentivize gameplay where you take your army of creatures and punch your opponents, and cards like Birgi, God of Storytelling and Frenzied Raider are designed to make boasting something you do in the game and outside of it.

: Tokens/Enchantments. Neat options exist in a go-wide strategy, cards like Battle for Bretagard and Maja, Bretagard Protector push a very token-based gameplay, while Calix, Destiny's Hand provides a nice Enchantment subtheme where you get to play with the Theros Enchantment creatures in a deck focused on them.

: Mill. Theros Beyond Death gave us two Ashioks. That's it.

: Giant Spells. Strixhaven introduced the Prismari, and with it, a new way to think about spellslinging decks. Why cast 4 small spells when you can cast 1 really big spell? Adding into the Kaldheim Spellslingers focused around Giants with cards like Aegar, the Freezing Flame and you have a deck designed to burn your opponent out with big, flashy spells in a Giant tribal-esque deck. Battle of Frost and Fire also gives Prismari a very neat boardwipe that can be non-symmetrical if the board state is right.

: Shapeshifters. This one was kind of difficult to figure out what to do, but Kaldheim gave us Moritte of the Frost and Absorb Identity, which synergize well with the Quandrix control deck.

: Discard. Theros gave us Kroxa, Titan of Death's Hunger and Kaldheim gave us Valki, God of Lies which fit in nicely with the gameplan of long, grindy games. Escape shows up in this color combination more than others and point is resource denial in every way.

: Self-mill. Acolyte of Affliction and Witherbloom Command are two of the most potent self-mill enablers in the color combination and giving green access to a bit of niche escape cards means you'll be able to capitalize on the graveyard a lot.

: Go tall. Two Gods in Klothys, God of Destiny and Xenagos, God of Revels fit nicely in with Kolvori, God of Kinship giving access a lot of very fun, very legend-focused decks!

Any suggestions are always welcome!