This is just the first draft, but I would like to update to a second draft before I start ordering cards.

Design Rules

1. I break these rules for things I like
2. No DFCs (I break this for Urza, Planeswalker since both pieces are useful here, and I want to see the meld happen once).
3. No one-off cards that imply a full deck exists to support them (e.g. Energy, Morph). Breaking for Chthonian Nightmare and will let folks know it's the only one.
4. No mechanically bothersome keywords (e.g. Daybound)
5. Minimize tracking of the gamestate (No Serra Paragon, Daybound, Dungeons)
6. No "surprise, you lose" cards (think Hullbreacher flashing in on a Windfall). I am worried Endurance may do this for the graveyard decks.
7. No persistent "can't" that directly stops what a deck should be able to do
8. Minimize unique tokens. Some one-off token producers are fine, but I don't want 1/1 white lifelink Vampire, 1/1 black lifelink Vampire, 2/2 black flying Vampire, and 2/3 black lifelink Vampire all together. (I break this for Young Pyromancer and Titania, Protector of Argoth
9. No special counters; +1/+1s, charge, and loyalty only. (I break this for Intrepid Adversary for a scaling anthem and Scavenged Brawler's ability counters since it exiles for cost and can thus be represented on the board as you would an attached equipment)
10. If a non-core mechanic exists, there should be a card using it with reminder text. There should not be a "what does Discover do" moment. I allow Map tokens because the tokens themselves explain Explore.
11. No limits on format, UB, border color, acorn, etc.

Gameplay Adjustments

• Drafting Urza, Lord Protector gives the player a copy of The Mightstone and Weakstone

Cards I Care Most About

• Tarmogoyf and friends - the new Goyfs from MH3 were a core reason I wanted to build this cube. None of them will ever leave.
• Sakura-Tribe Elder - I'm a sucker for this card's full art
• Urza, Lord Protector and The Mightstone and Weakstone - I need to see the meld happen

Concerns

• I have no idea what I am doing overall, this has been thrown together with a mountain of cards I like from scryfall whittled down via a couple "what are you running in these categories" series online and searching for discussion on individual cards.
• I am worried that 4 gold cards per pair at 450 is a lot. I also am counting gold as "basically needs to run in this pair" whereas something that is playable in 1 color sits in that color (Orcish Lumberjack needs R to play and G for forests, but Cruel Somnophage is a perfectly usably black creature). Hybrid is also multicolor just so I don't have to think about it.
• My curve feels weird. As I was cutting down, it felt like I started trying to keep my curves low and may have increased over time. No idea how to judge where I am with it.
• Kappa Cannoneer - Am I at enough artifact generation for this to matter and/or be too much of a game ender?
• Sheoldred, the Apocalypse - this card is strong, not sure if too strong in this list
• How is Ragavan, Nimble Pilferer in cube? I know it's strong in modern, but I know a lot of problems are not the same between constructed and limited.
• 3 Black 6s feels like too many. Grave Titan feels essential, Marionette Master is cool with the artifact tokens but I'm not sure there are enough, Massacre Wurm is the aggro sweeper. Not sure which to cut if I need to.
• Would it be weird to add Chthonian Nightmare with no other Energy support? I like it more than Recurring Nightmare as an aggro reanimator piece, but worry about signalling Energy as a deck.
• Endurance blows out the graveyard deck(s). I think it should be fine, maybe.
• Umezawa's Jitte and Lost Jitte are inevitable combat wins if not dealt with.
• How is my removal looking overall? Feels like there are places I have too much (White creature removal) and places I may not have enough (artifact removal as a whole)

Things I am considering

• As I was fiddling, RG as a whole gained a handful of the "cast from exile" cards, and it'd be pretty neat to add more support pieces to make the "cast from anywhere else" deck.
• May see about leaning heavier into Delirium
• Change some picks around to reduce unique tokens further.