Alright...
As I wondered about the relationship between the angiens and the shades and the icon of it discussed here, the I Ching came very much to mind, along with a suspicion that the relationship between the two species resembled one of the relationships between hexagrams.
So I of course asked the i Ching how to interpret this relationship: "How can I understand the angiens through the shades?"
The answer had some personal undertones, which I won't focus on here (Essentially, it's telling me -- but not you! -- to give up or expect very slow progress on this puzzle.)
P'i, with a nine in the fifth place:
12. P'i - Standstill [Stagnation]
-----
--ϴ-- above Ch'ien The Creative, Heaven
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-- --
-- -- below K'un The Receptive, Earth
-- --
"Creative/Receptive" reminded me of Mur's description of the relationship as "Question/Answer," and "heaven" reminded me of the wings angiens have.
There's a lot more to be made of this, but especially note the judgement and the image, which may describe both my relationship with this question and the relationship between the species:
The Judgement
Standstill. Evil people do not further
The perseverance of the superior man.
The great departs; the small approaches.
The Image
Heaven and earth do not unite:
The image of Standstill.
Thus the superior man falls back upon his inner worth
In order to escape the difficulties.
He does not permit himself to be honored with revenue.
Nine in the fifth place means:
Standstill is giving way.
Good fortune for the great man.
"What if it should fail, what if it should fail?"
In this way he ties it to a cluster of mulberry shoots.
By the way, above, Heaven (the creative) is turning into Flame(the clinging,) suggesting that Stagnation can become Progress. This might happen through the operator of Fire over Heaven, "Possession in Great Measure."
Fire in heaven above:
The image of Possession in Great Measure.
Thus the superior man curbs evil and furthers good,
And thereby obeys the benevolent will of heaven.
Necrovion won't change anything any time soon, this says (and with the recent turmoil there, I suspect recovery is not nearby;)
Following the shades will not lead to progress.
(source: http://www.cfcl.com/ching/)