Part 1 here
Part 2 here

White

I was already happy with most of what this color is doing so there are only a few changes here. I love the valiant mechanic from Bloomburrow so I'm bringing back Virtuoso and adding some mice to RW. Phelia I feel might be too strong for this environment with her ability to reset counters and delete blockers but I already have her so I might as well test her. With some good ETB targets in white she might also inspire a blink deck at some point.

Blue

Blue gets the fewest changes out of all colors and most notably trades two creatures for spells. Pteramander once again replaces Cloudfin Raptor for what feels like the third time. Malcolm, Alluring Scoundrel is moving out since I was never a big fan of the added complexity of his chorus counters. Plus, I felt like with a curve this low, by the time you get to four counters, you don't particularly care that you can free cast the card. Kitsa and Shoreline Looter are filling the same mechanical space with more interesting and less complicated text respectively.

Multicolor

For overall archetype changes see part 1. Most importantly, moves from full control to a tempo gameplan and moves from big guy stompy to a slightly lower curve with a cast-from-exile subtheme. All colors gain some additional themes which is reflected in many of the new signpost choices.

Colorless & Lands

The colorless changes focus on more artifact buildaround support plus Pip-Boy 3000 which I'm excited to try out. With the revamp of and Crashing Drawbridge no longer fits, and Lucky Clover goes along with the rest of the adventure matters package.

In the land section the biggest change is the move to fetchlands which replace all of the Thriving lands and those other random 5c fixers. Restless Ridgeline replaces Raging Ravine to avoid misunderstandings with double activations. There's also Talon Gates of Madara coming in which seems great.

At the top of the watchlist right now are all of the planeswalkers. I'm not happy with Liliana, Waker of the Dead since she doesn't really interact with combat except by removing stuff. Mu Yanling, Sky Dancer makes very large tokens and Archangel Elspeth creates tokens on + which is why I'm having an eye on these too. So far planeswalkers haven't been a problem but I'm also reconsidering what my goals are for these in the long run.

Besides that, with a space set coming up and sci-fi taking a much larger role in current releases, I've been toying with the idea of splitting sci-fi themed cards out of this cube to keep this one themed as fantasy-Eldraine-Bloomburrow-like and have a separate sci-fi-space cube longterm. But that's definitely a question for next year.

Part 1 here

are the colors with the greatest changes. and get major changes in how they play while mostly loses cards from the crossover that I wasn't passionate about anyway.

Black

Previously this color had the least tempo focus, generally being more about 2-for-1s and ETBs than proactive combat. Instead of looking for specific microarchetypes to define the color, I'm simply adding cool creatures with repeatable triggers, scaling, and combat relevance in general. Discard and graveyard stuff is still a big part of black's identity but other themes such as aggro, artifacts, and life loss are also represented now.

Red

Red loses most madness, some adventures, and part of its top end. It also loses the most creatures overall (3) and gains some new spells instead. Due to the lesser focus on adventures, "instant and sorcery card" effects like Dreadhorde Arcanist are back in as well. Shiny new tools here are valiant and the quasi-spectacle lizard mechanic from BLB which are perfect fits and cute on top.

Green

After testing the 1-2-4 curve from the last update, it ended up working a little too well. Powering out a 4/4 or larger turn 3 and then following it up with more of them was hard to deal with for other colors running mostly 1-3drops trying to scale up over time. So I've cut down on the top end and high p/t creatures and am adding some more interesting cards instead. I still like 2mv dorks to help green scale up a bit but early double-spelling should probably happen more often than dropping a bunch of massive creatures turn after turn.

Upgrades up to Fallout and Thunder Junction:

• Replacing the human tribal cards which also frees up some cards for direct upgrades that were only still in for their human type (Banisher Priest, Kitesail Freebooter)
• Continuing to expand the presence of artifacts and artifact tokens, including a Stoneforge Mystic + reconfigure package. I'll probably add more equipment, considering to bring back Maul of the Skyclaves because the power level has risen a bit since I cut it
• Redefining a bit more around a 1-2-4 curve with Cactusfolk Sureshot since Invigorating Hot Spring can be awkward without several 1drop ramp options
• and some other upgrades and experimental includes

Considerations for MH3 and beyond:

• Since I've been looking at turning into a more active playstyle (instead of mostly ETB 2for1 value and removal), this might become another discard-based color pair using cards like Psychic Frog. Will see if this works out while still making it feel distinct from and
• Not quite happy with some of the top end creatures like Voracious Hydra and Verdurous Gearhulk as they can flip the tempo of the game out of nowhere which feels like it goes against my vision for the cube. However any 5drop that doesn't provide massive value immediately is inherently questionable here so I'm considering to simply cap the curve at 4.
• Considering to change to an exile casting theme using Faldorn, Dread Wolf Herald and Bloodbraid Elf for a less top-heavy playstyle that also happens to synergize with adventures
• Considering to change to a flash theme with Nightpack Ambusher to make it play a bit more to blue's strengths and feel less durdly

I'm trying out some LCI cards and replacing some underperformers. Also looking at two longterm goals:

• moving black to a more tempo-oriented playstyle like other colors
• increasing the presence of artifacts to enable an artifact subtheme with the likes of Arcbound Ravager

Coppercoat Vanguard -> Astrid Peth
Repeatable artifact tokens + explore makes Astrid a great fit. Coppercoat is nice but a little one-dimensional.

Mage's Attendant -> Bygone Bishop
Attendant makes weird tokens, Bishop helps with card draw and artifact synergies. I'm lacking some creature token generation in white now so I'm thinking about something like Clarion Spirit but I haven't decided yet.

Spectral Adversary -> Malcolm, Alluring Scoundrel
Adversary's trigger was never really used while Malcolm's ability seems more relevant. Even the "ultimate" mode seems achievable with some proliferate effects or protection spells.

Stormchaser Drake -> Subterranean Schooner
One more artifact that is a noncreature at the same time for some additional synergies. And another explore effect to support graveyard synergies and blue +1/+1 counter decks. I never really committed to a full heroic theme anyway so Drake's out for now.

Nullpriest of Oblivion -> Cabal Initiate
Nullpriest is still decent but with a lower curve and no big reanimator targets anymore it's out of place now. Initiate is another instant speed discard outlet and growing body to lean black more into tempo.

Gravelighter -> Lord Skitter's Butcher
Gravelighter was awkward to play and not really necessary since there's more than enough removal already in black. So I'm giving the little rat a chance, which should play well enough and has a cute synergy with Piper of the Swarm.

Infernal Grasp -> Bitter Triumph
Straight upgrade and another instant speed discard outlet.

Conspiracy Theorist -> Inti, Seneschal of the Sun
"I'm you but stronger" - Inti kinda does what the other guy does but in a more aggressive way that also integrates better with all of red's archetypes.

Skyknight Vanguard -> Anim Pakal, Thousandth Moon
Anim is pretty much Krenko, Tin Street Kingpin except she triggers the turn she comes down and makes artifacts as a bonus.

Gloomshrieker -> Akawalli, the Seething Tower
I like Gloomshrieker but Akawalli is more in line with the tempo theme so I want to give the big guy a try.

Making some 1to1 replacements. Skophos Reaver gets an upgrade to its stronger sibling while others get sidegrades more fitting to the fairytale theme. Coppercoat is in since it fits the human subtheme and I didn't want to keep a 1of Afterlife card.

• Trying out some new cards and reprints from WOE
• Cut all the 6+ drops to lower the overall curve. Only high drops now are the cost-reducing adventure payoffs
• Cut all the cards that refer to "instant/sorcery cards" specifically to prevent confusion about adventures