Another potential option for discard could be Liliana's Triumph along with Liliana, Death Mage, which does take up 2 card slots but they're both noncreatures
I just realized that, with Kinnan out, Chandra's Embercat taps for an unrestricted red mana (as well as a restricted one). So, Crash Through (drawing Archipelagore or Sea-Dasher Octopus) + Fry could work as a red stage. However, it obviously doesn't work with the current life stage, and it also breaks the black stage by being able to draw skull prophet instead of reanimating it. (it would need to go before the black stage since embercat dies to ritual of soot).
But if we could find a way to make it work with the black stage then it would eliminate the need for Bolas's Citadel, opening up more options for layer extensions. And if we could somehow find a way to make it work with a life stage too then that would be amazing.
Edit: Those layers look good. At first I wasn't sure how the stage worked with Sheppard of the flock but now I see that you can put the the mutate creatures onto the battlefield with Kinnan and then pick one up.
Rowan can be infinitely recycled, which is an issue. I believe the rest looks good.
An idea I had was that moving to the end step triggers a lot of copies of Gadrack, The Crown Scourge, and each trigger makes a lot of treasure tokens. But that doesn't add an extra layer here.
Could Escape protocol be used for anything? It can flicker a creature/artifact for whatever colour of mana we need to spend. But that doesn't seem to be too useful; it can't untap Nyx Lotus for instance.
Hmm, doing it that way allows the opponent to choose what their sagas steal, which would mean we somehow need to ensure that the lotus is the only permanent on our side of the field when theirs go off.
The issue with giving all creatures haste with Domri is that you can have a bunch of hasted porcuparrot tokens, and go through the life stage mutating onto the tokens instead of the nontoken one. Then, every 4th porcuparrot gets killed for free by the pings from 3 others plus itself, saving the use of a shock and thus generating life. Some pings (and shocks) can then be directed at the Domri to recycle it, going infinite.
Edit: Oh, I see, with mythos we won't need dance at all to copy our TYSs. And if we can't make an enchantment have any other type, or remove OWTS, then the opponent can't get anything other than an enchantment.
The big issue with Mythos of Illuna is that is that after using it once with all the colours, the fight effect is part of that permanent's copiable values, meaning it retains the ability when copied by Quasiduplicateand thus can gain life (and kill stuff) way too cheaply
Minor optimization: Replacing 2 basic lands for Azusa + Fabled Passage gives the same number of landfall triggers overall, but allows 2 lands to enter untapped, giving a small improvement to one of the layers that is not enough to affect the final number.
Regarding the opening, the lands don't all need to be plains I believe; we can mutate a greathorn to fetch a mountain in order to cast a shock, killing the skull prophet. We can then shuffle it in and recast it for 2 life, leaving us on 1 and generating some black. But then we have no cards in hand to cast the mentor...
Edit: Oh, greathorn lands enter tapped.
Edit: Azusa would allow 2 more untapped lands during the opening; in particular from FortyTwo's start above we could play Azusa, a mountain and a swamp off the top, Duskfang Mentor from hand, then activate the ability on leafkin avenger
But if we could find a way to make it work with the black stage then it would eliminate the need for Bolas's Citadel, opening up more options for layer extensions. And if we could somehow find a way to make it work with a life stage too then that would be amazing.
Edit: Those layers look good. At first I wasn't sure how the stage worked with Sheppard of the flock but now I see that you can put the the mutate creatures onto the battlefield with Kinnan and then pick one up.
An idea I had was that moving to the end step triggers a lot of copies of Gadrack, The Crown Scourge, and each trigger makes a lot of treasure tokens. But that doesn't add an extra layer here.
Could Escape protocol be used for anything? It can flicker a creature/artifact for whatever colour of mana we need to spend. But that doesn't seem to be too useful; it can't untap Nyx Lotus for instance.
The issue with giving all creatures haste with Domri is that you can have a bunch of hasted porcuparrot tokens, and go through the life stage mutating onto the tokens instead of the nontoken one. Then, every 4th porcuparrot gets killed for free by the pings from 3 others plus itself, saving the use of a shock and thus generating life. Some pings (and shocks) can then be directed at the Domri to recycle it, going infinite.
Edit: Oh, I see, with mythos we won't need dance at all to copy our TYSs. And if we can't make an enchantment have any other type, or remove OWTS, then the opponent can't get anything other than an enchantment.
Regarding the opening, the lands don't all need to be plains I believe; we can mutate a greathorn to fetch a mountain in order to cast a shock, killing the skull prophet. We can then shuffle it in and recast it for 2 life, leaving us on 1 and generating some black. But then we have no cards in hand to cast the mentor...
Edit: Oh, greathorn lands enter tapped.
Edit: Azusa would allow 2 more untapped lands during the opening; in particular from FortyTwo's start above we could play Azusa, a mountain and a swamp off the top, Duskfang Mentor from hand, then activate the ability on leafkin avenger
From where we are, we could perhaps Caviler of thorns to find a Radiant Fountain? It doesn't matter what the extra lands in our deck are.