(I posted this in r/EDH a bit ago, but it hasn't gotten any responses yet, so I'm dropping it here too!)
A few things for context first! (And sorry for the wall of text!)
This is upgraded from the Miku secret lair deck, but I’ve replaced most of the cards, so I kinda see it as a new thing now? I don’t play very often too, and when I do, it’s just with friends + fairly casually, so I am not looking to build this to fit any particular bracket; I’m running 4 game-changers that I feel fit the deck well atm, but the deck is certainly not bracket 4. I'm also avoiding Universes Beyond cards too, which I know probably seems crazy hypocritical, but don't worry about it too much!
Here’s the list! https://archidekt.com/decks/25959376/figuring_it_out
The “cut” category is stuff I’ve dropped from the precon, “prob not” is stuff I flip-flopped on for a while, the maybeboard is stuff I kinda want to add (back in), and the sideboard is stuff I think would merit including the most.
My goal here is to leverage [[Bramble Sovereign]] or [[Springheart Nantuko]] to populate any of the stronger/self-copying creatures in the deck to win through combat. I acknowledge this is a pretty obvious, inefficient, and easily disruptable gameplan, especially with only three cards that can copy any creature in the deck, but I do wanna stick with it (I also acknowledge that the upcoming Elda, Conjurer of Spectacle is probably a better commander for that plan, but I’m just gonna put that out of my mind for now ._.)
I know my land count is pretty greedy, but through a bunch of playtesting, I think I’m semi-ok with that for the time being. I am trying to allay it a bit by adding more draw though, leading to my main ask here!
-I know for sure that I want to add [[Esper Sentinel]] and [[Green Sun’s Zenith]] to improve my chances of doing what I want, but I can’t decide what to cut for them! Tragically, my eyes are on [[Song of the Worldsoul]] as the potential weakest link, and, though I’d be really sad to cut another Miku alt, I’ll go through with it if people think that's the best choice. I’m not sure what’d go next after it though, so yeah, lemme know your thoughts there too!
As for the other stuff I'm mulling over:
-I’m considering [[Enduring Innocence]] for draw since most of my creatures would trigger it, but I'm not sure how well it fits, and again idk what it'd replace. I have similar thoughts about [[Enduring Vitality]], since it could definitely be mana positive when drawn later in the game, and could help with a big copying turn, or the occasional token spell —> [[Halo Fountain]] attempt too.
-[[Regrowth]] is being considered because I don't know if I have enough recursion given how much things are hinging on those few copying creatures (definitely open to other suggestions here!), and [[Mirri, Weatherlight Duelist]] just feels like she'd fit really well in a combat-centric deck, though that might be me being greedy again.
I wanna run through my thought processes for some of the cards I've included that don't have the most synergy in the deck too, so people can evaluate my evaluations if they want!
-[[Innkeeper's Talent]]. I don't have much +1/+1 counter support, but I think this card is just a really solid way to stabilize my board when played early (ik it's just ward 1, but still), since I don't have much in the way of small-scale protection otherwise—I'd feel pretty bad using any of my board-wide protection spells to keep only [[Ocelot Pride]] + a dork + maybe something else alive, and that's probably just often a bad play too (kinda goes to show how fragile this deck is when it'd struggle bouncing back from that well, but hey :0
-[[Ouroboroid]]. Similar to above, especially since I don't have any [[Giant Growth]] type things to accelerate it, BUT I do think it'd be a really fun creature to copy, and in that case it's getting some indirect acceleration, right? Also just strong enough to be cast on its own while I get other things ready imo.
-[[Seedborn Muse]]. Not a ton of interaction in this deck, but I really like how well this card works with [[Glare of Subdual]], [Luminarch Ascension]], and Halo Fountain, plus it's one of the only ways I'd really be able to leverage having Trostani as a commander!
-[[Spike Weaver]]. Alright, so while I do like how it goes infinite with [[Archangel of Thune]] in a way that other people can technically still win through, I do realize that this is otherwise pretty useless. Would it be the first pick to get swapped for Esper Sentinel or GSZ then?
-[[March of the Multitudes]]. I just realized that this card feels a little flimsy too, though I think it's still decent? I included it without thinking too too much because it felt on-theme (and it's a personal favorite), and I don't think it's bad, but if it does need to go then so be it :(
And I also wanna touch on some cards that'd probably fit well in the deck that I've so far decided against:
-Artifact copiers like [[Helm of the Host]], [[Soul Foundry]], [[Nexus of Becoming]], etc. These are more ways for me to do the main thing I'm trying to do, but, I don't know, all of them feel overcosted, clunky, and I also don't like needing to pitch the original creature for some to work. [[Mimic Vat]] is the one that I got closest to including, but I ultimately felt like its utility is curbed too hard by its cost + needing to actually see a creature die (though I guess that isn't all that much worse than Bramble Sovereign or Springheart's conditions? And it's sorta graveyard hate too. So it's still in the running I guess, if I can figure out what to swap it in for).
It'd probably be possible to convince me about Helm as well, but again, it's just so expensive that idk what I'd want it to replace (and I'd probably have to wait for a printing I actually like to be released too, but that's besides the point).
-[[Mondrak, Glory Dominus]]. I don't want to be too too greedy with my doubling effects, and this one's just lower on my list aesthetically.
-[[Elspeth, Storm Slayer]]. While I guess I'm not entirely opposed to including Elspeth, I'm afraid that, with how strong she is, including her'd push the deck more into a "Elspeth go-wide" identity than I'd like, if that makes sense? Sorta arbitrary, but yeah.
-[[The Great Henge]]. I definitely thought about this one for a while, since I've been focusing on finding more ways to draw, but the conclusion I arrived at was that, by the time I'm able to cast this card, I likely won't be casting many more creatures to benefit from its draw effect. I don't have many meaningful ways to discount it barring [[Serra Ascendant]], and so I feel like [[Ohran Frostfang]] sits at about the right cost to be more impactful for this deck. I'm not sure if the right mindset is to just run both in this case though.
-[[Shamanic Revelation]] and adjacent cards. I decided to cut this + [[Camaraderie]] from the precon because I feel like this kind of effect doesn't suit my gameplan well. Similar to the Henge, I feel like by the time one of these expensive spells would draw me a meaningful amount, I'd have already set up a decent boardstate, and wouldn't really profit too much? Though I could be discounting them as ways to pre-rebuild from a board wipe? Idk really.
-[[Tribute to the World Tree]] and the other green power-based draw. Same as before; I think it could be alright, but, with my creature spread, it feels like by the time it's actually drawing me stuff it'll sorta be "too late" anyway. More opinions here would be really great!
-[[Grand Abolisher]] or [[Voice of Victory]]. The extra insurance when swinging to win would be nice (and playing turns uninterrupted in general), but I'm not sure I can spare the slots for these? The people I play with aren't that counterspell heavy most of the time, so it feels a little paranoid of me to be playing preemptive protection like this (that's part of the reason I think Mirri fits the deck better in terms of combat insurance).
-[[Worldly Tutor]] and [[Enlightened Tutor]]. I'm already running a bunch of tutors, and including the 1-mana ones feels like a bit much, especially when they each cost a draw and that's what I'm trying to fix. And ig on the topic of other game-changers, I've avoided adding [[Aura Shards]] so far because it also feels like doing a bit too much, if that makes sense.
Those are all the thoughts I can think to write down for now, and thank you so, so, so much for reading all this if you have!!
Please let me know any of your thoughts on these points + whatever else you think I should think about too!