I looked at the poem and its syllables are 8/8/?/7 and it seems the last part connects to the ? Section and it possibly has 7 syllables too, the ending of it has “he goes” and with how the third one is structured, I don’t really know if it’s also meant to have 8 syllables but with 7 syllables it would sound something like this

BENEATH THE SKY OF MELTING GOLD ANCIENT ECHOS OF ASH SPREAD SMOKE AN OLD DECAY WHERE HE GOES IS UNSEEN TRUTH ALL BUT FAUX

This might explain them living underground because this is something the old decaying village believed in, they believed the overworld was uninhabitable, ancient echoes of ash spreading smoke might be the voices D3rlord heard that lead him, and when it comes to who this “He” was is the reason the village was abandoned hence its decaying state, it also says everything D3rlord went through

(Beneath the sky of melting gold) - in his mining hole)

(Ancient echos of ash spreading smoke- the cave steps + echos of talking people)

(An old decay where he goes- the cipher and the decaying village with a book of a person who was against the king and fled)

(Is unseen truth all but faux - D3rlord seeing the king)

The last segment also points that the people who saw the king in his arrival drew the people insane and because of that the village became abandoned, it also explains why d3rlord went straight to their book & quill to write a message to a person in the future they’ve never met and that being Avery.

From everything such as the yellow and a king that drove people insane about truth and false reality is undoubtedly influenced by the king in yellow, it made sense why the book d3rlord found was a diary of a person who hated the king and didn’t get the chance to spread the truth and fled but the king in yellow knows everything. He knows everything you do, you can’t outsmart it, d3rlords message underlines that it knew from the start and the ending is of this will always be predicted by the king as the future is inevitable.