Formaldehyde (ver. 4)

[dukealien]

Thanks for sharing this - a good read.  General comments at the end, line-by-line for specifics, mild critique.

1

The empty roads are black with bloody pools  nice alliteration - might try an unusual verb in place of "are"
of prophets killed for spreading different views.  minor meter problem if "different" read with 3 syllables.  Use a different (g) word?
I cut their corpses, cold, for breaking rules  inversion (of "I cut their cold corpses") but removing the commas gives a variant of "cut [them] dead" - just a thought
and carve this priceless proverb just for you:  "just for you" somewhat cliche - try for more unusual with same rhyme?
a satellite in orbit is sublime,  could capitalize "A" to stress that it's start of the quoted inscription.  No comma needed.
but falling to the ground disintegrates.
The stars and planets spin in rhythmic time – 
from order they can never deviate.  inversion (of "they can never deviate from order").  One solution might be to move the dash from previous line to before "they" and reword "from order" so it fits.
If telescopes don’t help the blind to see,  is this comma necessary?  Also, might consider "can't" not "don't."  And... we're no longer in the inscription, are we?  (See at end.)
then I must lead this city from the dark  perhaps "its" for "the" - more specific
and desperate days. They feebly follow me
like beasts of every kind into my ark.
But only one remains in Herald Square:
a poet which no diamond can compare.  Need to free up a syllable here to allow "a X with whom no diamond..."  "Skald" comes to mind, but is foreign/antiqurian.  Or go metaphoric, "gem" or "pearl."

2

She writes her poems in pencil, sharply pressed –
each word a silent poison on her lips.  This is very good.
A selfish swipe – her sorrow – won’t divest –  don't like "divest" here; could change both it and "pressed" in your search.
that carbon chisel from her fingertips;  "graphite" for "carbon" - just a thought.
and when she writes of Armageddon’s breath,  since you're about to describe it, "while" for "when?"  Also, no comma needed.
it whispers, hanging low in hopeless air,  no comma needed at end of line
where cigarettes, extinguished, promise death  sounds well but slightly illogical - something more like "where cigarette butts smolder, pressage death" or the like.
for bodies that, not broken, self-repair.  I get the thought, but needs a subjunctive "if only they hadn't been broken [by smoking]."  Difficult.
The waves of warmth exhaust from dirty throats  Word choice - "But" for "the," "sooty" for "dirty" for example.
with gaseous glow of neon embers, bright.  Beautiful line, might do without the comma.
As fatal floods ascend the poet quotes  "fatal floods ascend" is lovely
a fool who gently slid into the night.  "gently slid" is nice, but "into" breaks the meter.  "[S]lid home into night?"
Her final song was written with a pen
and she apologized for dying then.   Really wanted to hear something about the pen here.  It wasn't her usual pencil, but how did that kill her?

3

Though crystal waters had receded fast,
they couldn’t clean the stains of mortal sin.  "Cleanse" perhaps?  Need a word that says "erase."
An asterisk was set, the die was cast:  Caesar cliche, the baseball asterisk much better
a line between – a curtain closing spin.  comma for dash, then hyphenate "curtain-closing?"
The body reached a point of full decay "its" for "a?"
and quickly passed on through a cloudless sky, is this comma needed?
while I, with heavy heart, had run away  perhaps vary the cliche - "while, dragging heavy heart, I ran away?"  (Pardon the rewrite)
and begged her God above to let me die.  "God above" - forgiveable cliche.
But life, he said, was worth the pain of loss,  for a bit of class, capitalize pronouns referring to a monotheistic deity - "life, He said"
and I, he said, had best accept the fall.  could capitalize "he" and even - to take it a step further - "[F]all"
In time his wisdom grew on me like moss  could capitalize "[H]is" in this line and the next.
and plainly showed his writing on her wall.  nice variation of the cliche "[hand] writing on the wall"
Formaldehyde will not preserve for long –
With me, the stars will always sing her song – Just a period, I think, though your dash is better than the three-eyed ellipsis.

Pick on everything you can. Continuity, word choice, punctuation, whatever you like. Title suggestions welcomed. Anything and everything. Please.

More general notes:  In Stanza 1, there's an unmarked shift from the inscription to a soliloquy (speaker as Noah) the speaker would *not* want carved in stone.  Could the inscription be italicized or even placed in double quotes?

Going through line-by-line, I fear I've overdone for mild - please take even the most hortatory above as gentle suggestions.

The triple sonnet is intriquing and mostly well done; the closing couplets of sonnets 2 and 3 could use work.  Likewise use of the inversion:  push on the line a little harder and it's almost always possible to use conversational word order.

An engaging triptych - hope to see more of it.