My only disappointment is that there's no Nurikabe. Just one Spirit or Enchantment Creature Wall.

Lot of winners in in particular for me, like Dockside Chef and Unforgiving One

I'm really eager to find out what limited will be like with this set. There are a lot of pretty unique mechanics. We have ninjutsu encouraging evasion and EtB abilities. The Samurai mechanic encourages attacking alone. Reconfigure and modified will lead to some weird incentives and decisions. And we've got these weird suspend creatures with upside in the form of the sagas.

By the way, here's what the signpost uncommons tell us about the limited archetypes:

WU vehicles
UB ninjas
BR artifact sacrifice
RG modified
GW enchantments
WB balance (artifacts+enchantments)
UR artifacts
BG not obvious, but maybe there's an etb + ninja thing going on here
RW sumarai exalted
GU channel? maybe a strategy where you slow your opponent down until you can play a big evasive finisher?

Black-green is graveyard recursion and green-blue is channel. They've said before in a stream.

Oh, now I see the channel synergy. Skyturtle can get back stuff you channeled earlier or bounce something in order to channel it. Cute.

I feel like there aren't a ton of graveyard recursion cards in black-green, but it does synergize with channel at least, so maybe it'll work.

Thanks for the info.

Yeah when playing with draftsim, black-green recursion doesn't seem to do much. It's more like a general 'good stuff' deck with like value here and there but those tend to fail against actual synergies.

Mirrorshell Crab

A lot of Pauper players (specifically Reanimator and Tortured Existence) are excited for this.

I love the symmetry of Mirrorshell Crab countering spells and abilities unless their controller pays both when you channel it and when it's on the battlefield.

I wonder if the artifact + enchantment is the closest we'll get to Starstill's mastery mechanic. I was wondering during the early previews if some of it was setup for a future type-matters block, but I think this WB archetype is the payoff we're getting here.

Mastery is the same thing, but with Creature or Land, right?

Kinda feels like it's about the same tbh; of all the permanent types, creature and land are so integral to regular gameplay that having one is a pretty trivial task, and planeswalkers are restricted to Mythic rarity so having a named mechanic requiring one seems like a bad idea. So that leaves artifact plus enchantment.

That ramble out of my system, I wonder if there is any possibility of a set that combines Instant and Sorcery themes with Artifact and Enchantment themes?

I feel like it could. Strixhaven was all about magecraft but Lorehold had stuff like Osgir and Alibou for an artifact bent to their Commander contribution, which I think could have been leaned into more in the main set. I don't think it would be hard to have a magecraft faction and an artifact/enchantment faction, especially if both themes can unite under the "noncreature spell" banner the Jeskai had going. If I had more time I could probably spitball a set of signposts/archetypes that could all overlap to care about some combination of Instants/Sorceries, artifacts, and/or enchantments.

Mastery is "If you control an artifact, a creature, and an enchantment". I'll grant that creature's usually pretty easy to get, but it's not quite a given. Land was a real given and was kicked out of the mechanic early on.
Starstill was the "types matter" set and had a inst/sorcery theme and a artifact theme.