Flash, Instants, Cycling, Scry. Almost nothing that doesn't not have an instant speed option. Things that do have a big payoff but at a big cost of tapping out. Everyone is holding out for end step, things happen on the stack. Very tense games, counterspells are king. Combo's and flash beats abound, aggro options will very non traditional, or perhaps lean into more direct damage. Blue hosers shall abound, all the anti blue green hate like seedtime go way up. Maybe stack subthemes, like surge, storm, werewolves, addendum, the fated cycle. The opposite of prowess. With all that scrying miracles seem cool too.

Instants are the last big pull I got to do with the gatherer checklist method I've devised. 2613 currently (and always growing), like 26 full pages of checklist. I got about 40 minutes left at my work computer today, and this is bigger than a 40 minute job. I should be able to really sculpt an interesting cube from this full list though.

Actually the excel/gatherer/list import from checklist takes less than 20 minutes, so shazaam! I've got some cleaning up to do in terms of numbers and manual entry of split cards but damn that's efficient.

What's more is that if I get my cards inputed into an excel this way, I can appaise my whole collection pretty easily.

In the sideboard are the trumps. Spells that be countered or have split second. I have to be thoughtful about how I use these cards in the cube. Trumps are an important part of the stack in their own right, but I don't want to provide an overly simple way to ignore the stack. Players should do well in the cube because they understand and have mastery over the stack. Also, What trumps are too good versus what is interesting? Carnage Tyrant is likely too good, but what about Great Sable Stag? Also I could use trumps to balance the color pie. For example, outside of through the breach, I have not identified a way that red put's creatures in at instant speed. Perhaps to make up for this defecit, they could have the lion's share of trumps.

The Stack is a cube environment that rewards and teaches players the ways of the stack. An Advanced concept, but basically everything being done for the most part at Instant speed means that those who can manuveur timing and the stack should do better. Also, the most iconic flash spells gain admittance.

So creature balancing is a little trickier than usual. Red and Green get werewolves which are probably some of the biggest "The stack matters" cards for those colors on creatures, so they need to be playable in the cube. Luckily all of the low drops upgrade really well. We start to get in trouble with 3,4,5 drops, as many are below rate and not neccessarily worth the restriction. For these to be good, many creatures at the same CMC need to be appreciably weaker for these to be played. For example, if many of the best 5 drop flash creatures look like archangel avacyn, Gatsraf Arsonists is going to be pretty bad. If instead they look more like 5 3/3 flying flash, that's more compatible. We also trim the top end werewolves, leaving the low drop wolves as good payoffs.

So what's my plan here? I'm going to cycle multiple times with these big pulls. I need to do some parameter setting and work backwords. I do like my 450 usual for variability, but a 360 cube might make the concept tight. Let's tray a 360 version. A Concise battle of the stack, as opposed to the larger exploration of a theme. This might help the non-blue colors show off what they can do more. Stack matters versus all the good flash stuff. What if it was about 1 artifact per pack, 2 land per pack, 2 multicolor, and then 2 of each color?

24 Artifact + a little variance= 25
48 everything else + a little variance= 50 everything else
375 cube
For Cards of Color, 2/5 threats (20), 3/5 (30) interaction seem right.

So far my initial pull from red has reinforced some lessons about the stack for me. Mastery of the stack is not just a preponderance of instant speed effects. Mastery means skills around evaluation of what you have and what your opponent has both in hand, in their deck, on the field, and what mana they have available. It means creating lines through interaction. Card advantage and mana advantage are key aspects of winning a fight on the stack, so these need to be non-issues for the cube. Fixing should be somewhat automatic, meaning high end land cycles and perhaps signet's. Card advantage should be available to all colors, so i need to actively prioritize 2-1's in all colors and low cost artifacts that assist in this as well as selection. Also the reason why cycling and scrying are desirable. Green's ability to put lands into play are a key feature, but can get overwpowering. I think it will be pretty feasible to seed the cube with enough anti-blue tech to keep the counterspell wars interesting.

Deciding on utilizing bouncelands and flip lands I an incentivized to play things that flicker only your own permanents (if it hits lands) and limit the number of boomerang/LD effects as they will more powerful than they ought to be usually. I've also realized that a smaller cube size enables me to have more specific combos like splinter twin, pergrine drake, Ral, Storm conduit but not bigger combos like storm.