(Choices I excluded due to not finding the right card)
Grimm:
I just couldn't find a card that I liked enough as Grimm. Most likely a vampire like
Necropolis Regent or the double-faced
Bloodline Keeper
would be the best choices, but at the moment I'm unsure. Maybe I'll find the right card for him sometime.
The Dreamers:
A way to represent them might be nice, but I'm not too bothered by this one. After all, they're far from being active in Hallownest anymore, trapped in their eternal sleep. Besides, I have a few cards associated with them, Lurien at least.
The Wyrm/Pale King: Now this is a bigger one. I wasn't sure what could properly represent such an enigmatic character, so I figured it was best to leave him out as well. He's gone by the time the events of the game start anyway. Perhaps though I could find something to represent the Wyrm's remains. I did consider Worldspine Wurm but it's a little bit too... Alive. I guess technically I do have this Plains.
White Lady: This is an inclusion I really wanted, but again, I just couldn't find something that worked quite right. I feel it's likely that a proper card exists, though!
Unn: Seemingly lore-relevant, though we know practically nothing about this creature. I'm fine not having a card to represent them, though it wouldn't hurt either.
Mister Mushroom: Definitely would have been fun to include this weirdo somehow. Ghave, Guru of Spores might have worked, but he felt a bit more active than I'd expect from the guy.
(Ones I excluded for other reasons)
The Abyss: I'd ABSOLUTELY include this, if only it didn't command a price tag large enough to buy a palace's worth of buzzsaws. Reserved list strikes again...
Exploration: Similarly, a rather high price keeps me away, but to a MUCH lesser extent. I expect to see this one in here at some point.
Cartographer: Okay this is a pretty perfect Cornifer. But it doesn't have a whole lot of synergy, and Cornifer's not exactly one to join a battle anyway. I'd still like to include it at some point though. Cornifer deserves the love.
Guard Gomazoa: This one was SUPER tempting as Uumuu, the jellyfish-like boss encountered in the Teacher's Archives, but it ended up getting cut. I feel like it'll likely end up in the deck at some point though. Speaking of the Teacher's Archives, Breeding Pool is perfect for it, but I still gotta get one. It'll 100% be in here though.
Lord of the Void: Okay, the Void Entity/Shade Lord is a character that I find really interesting, but I feel like it's not as well known as some other aspects of the game, so I decided against it. I still think this is a pretty cool representation though!
Door of Destinies: The door in King's Pass... Sheesh, why didn't I find room for this? So many cards I wanted to use, but sadly only so many spots to use them.
Arachnogenesis: The spider enemies in Deepnest. Definitely one that I'd like to acquire and include at some point.
Luminous Broodmoth: Honestly, it looks a lot like the Radiance, and it's a sweet card. But I already had Atraxa, so I couldn't find a specific slot for it. Maybe sometime I will though!
Clockwork Beetle: A fun option for the mechanical void creations in the White Palace, but I decided against it due to them never appearing (alive at least) outside of a dream.
Crystal Vein: I kind of just forgot this card existed. I'll probably get it in here sometime haha.
Swarmyard: A bit expensive, but very worth an inclusion when I can get one. It's definitely got a Deepnest vibe to it.
Relic Seeker: A rather perfect Lemm, but I figured Lemm might be another character not recognizable enough to prioritize.
Fungal Sprouting: Another that I didn't really have a reason not to include, it just happened to get cut. A shame too, since Fungal Wastes got a bit underrepresented. Maybe I can find room for it.
Docent of Perfection
: I actually really like this creature as Soul Master/Soul Tyrant. One of my most likely inclusions to the main deck from here.
Verdant Catacombs: A better option for the Traitor's Child's Grave than Woodland Cemetery but far more expensive.
Seal of Cleansing: The seal placed on the Black Egg. This is one of the first that I'd like to make room for as well.
Killer Bees: I really wanted to include this... It's got so much Hive Knight energy. But the mana cost is tricky, and it has flying which is a bit strange for him.
Nimbus Wings: The Mothwing Cloak. Another that I just forgot existed for a while, but it's really perfect.
Blightbeetle/Broodhatch Nantuko/Endless Cockroaches/Nantuko Vigilante/Bane of the Living: Some stand-ins for random enemies that didn't quite make it either.
Deadly Grub: I just figured that Grub Mimics were a pretty uncommon enemy. I also feel like more grub stuff should be in here in general... Maybe Metamorphosis?
I had to cut a LOT of stuff that I wanted to include and it's a bit sad, but also, I'm so happy with how well this project worked out!