Dust to Dust
This is an entry for the 100 unique cards 360 cube contest.
Structure
Every card has cycling.
Excludes cards that would be obviously broken in this environment.
100 unique cards: Each color has 15-16 unique cards, plus 6 unique gold cards, 5 mana rocks, 5 duals and 5 monocolored cycling lands.
360 cards: There are 3-4 copies of each creature card, 4 copies of each Crystal, 3 copies of each other noncreature nonland, and 7 copies of each nonbasic land.
Dynamics
Apart from basic lands, every single card in your deck can be cycled away.
The environment is extremely slow, so the first turns are usually spent sculpting hands and measuring the opponent's moves. Then, decks shift into low-power battlecruiser Magic.
Fringe aggro decks can be built to exploit the sluggish starts.
Colors
Duals are allied-colored, and crystals are wedge-colored, so fixing is a bit better for ally colors, but enemy color pairs are also supported.
The slow speed and extremely high density of smoothing make the environment receptive to 3+ color decks, though the payoffs only are the Resounding cycle and access to more cards.
Power level
The power band is wide, and the power level is very low. Angel of the Ruins, Nimble Obstructionist and Expunge are among the best cards.
Board positions revolve around large creatures. Card advantage is incremental and slow.
Archetypes
Macroarchetypes
The emergent macroarchetypes have tools to be viable in at least one seat.
Aggro / Aggro-Control
Aggro is slow here and does not have much redundancy, but can capitalize on the general glacial speed of the format. Running removal, tempo spells, discard, protection and reach is necessary as there isn't enough creature density, and effective, as they match up well against expensive spells.
Midrange / Ramp
7-drops naturally synergize with ramp, and getting to them two turns earlier is a great step. Due to cycling being on every card, ramp decks suffer less to variance than usual. Decks will always have a plan for large creatures though, so a more refined plan with resilience, card advantage and protection will be more successful.
Control
In a slow environment, being the slowest deck is often the best plan. There is plenty of time to setup and the usual tools of control are available - removal, board wipes, card draw, finishers. Control plans to get to 10+ mana and achieve inevitability.
Microarchetypes
Burn
Mill
Zombies
Five-Color
Fliers
Specific card inclusions
Though Astral Drift might look broken in this cube, it's hardly ever worth blinking a creature to reuse its ETB, because the only targets are Angel of the Ruins, Quakefoot Cyclops, Rooting Moloch and Orchard Strider. Astral Drift is more like temporary removal.
Complicate is the only counterspell. Keeping up plays around the Dismiss mode, while keeping up plays around the Mana Leak mode.
The list contains 7 enchantments and 5 artifacts (out of 100 unique cards) so there is a moderate amount of targets.
The Ikoria Crystals allow decks of any colors to accelerate, though green has extra ramp.
Specific card exclusions
The Triome cycle would fix enemy colors more than ally colors like crystals, and to better balance the color combinations, the Bicycle lands were chosen instead. Cycling Bicycle lands is much more reasonable, and they seem to be more in the spirit of extreme smoothing. This also keeps the cube's price much, much cheaper.
This was in early iterations, but it hosed aggro unnecessarily and is never actually cycled, so it went against the spirit of the cube.
Renewed Faith is low agency and pretty much always cycled unless it's obviously needed. It hoses burn too easily.
I wanted a simple tax structure so that playing around counterspells is possible. In the end, I like how Complicate creates a three-tier space, and I chose not to include these option options.
6 and 7 drops need to be castable, and having 3-mana counterspells that always trade with them, and can't be played around would be unhelpful.
Memory Leak would be a powerful card in this cube, but watching what your opponent is cycling and the tension of guessing what they have in hand and trying to cycle the right cards away is a centerpiece of the format. Looking at the opponent's hand takes it away.
Ash Barrens feels like fixing, rather than cycling.