I'm really wondering about the order of events we learn of in "The Midnight Star" (MS) poem if only because some pieces of language aren't quite meshing with what we've previously known / potentially assumed
Elarion, trembling seed, lay down to earth in icy night, and in the cold her roots took hold defying winter’s deathly bite. Elarion, fading bloom, afraid to wilt and dim and die, she searched the dark for but a spark and caught the dragons’ hungry eye.
We know Elarion was an early human settlement that eventually became the biggest in ancient Xadia (TOX). We know that this is happening prior to the stars leaving thanks to a later stanza. Moreover, this stanza indicates that the city was drawing the attention of the dragons, which is also hinted at in Ripples, "It happened long ago, when humans had only just learned to hold fire in their hands without burning. They nurtured their precious primal flames secretly—in the dark of night, beneath shadows and shrouds—as cultivating its glow drew the eyes and ire of monsters".
However, Elarion suffering and struggling to hold on doesn't quite make sense if it already had primal magic... unless the first stanza condenses these events, i.e. "she searched the dark for a spark" ("that secret becomes a spark, the tiniest flicker of a primal source inside you") and that's why the city initially caught negative attention from the dragons. But even then, that contradicts statements from Ripples, in which:
"he did not know the stars as I know them. He did not know their arrogance, how they had rejoiced to look down upon their newborn sea. Where once they’d watched errant flames burn with pride and undeserved power, there was now only stillness"
the Startouch / First Elves are the ones who — seemingly — cast Aaravos out and create the sea as an initial punishment for humanity because "humanity had been given something they were never meant to have."
But MS doubles down that it's the dragons threatening the city, and that humans are still assuming the First Elves might help them, only for the stars to refuse and leave:
Elarion, frightened waif, reached bone-white branches to the night, the stars she asked their light to cast and stop the dragons’ fiery might. Elarion, unworthy whelp, Wept as the stars turned black the sky, They donned their masks They turned their backs, And left Elarion to die.
So Elarion/humans have been given primal magic by someone, who is probably Leola, a unicorn who may or may also be a startouch elf even though the First Elves disapproved (TOX, book 1: novelization). This makes the other First Elves angry and also seems to anger the dragons. When Elarion asks for protection from the First Elves against the dragons, they're ignored/abandoned.
This is, however, where MS starts to get tricky.
Elarion, dying husk, did wilt and whimper in the dark, ‘till the last star Reached from afar His touch: a blaze, a gift, a spark.
Again, we see a spark, which has most been referred to in reference to primal magic, even seemingly earlier on in the poem. We also see gift, which seems like a blatant reference to dark magic: "So he gave us magic!" (4x07) and "Lay [the staff] down? But it was a gift" (3x01). We can also read it into this section from the Puzzle House in which Claudia quite explicitly uses magic that isn't primal, either:
He said it came from "a spark of fun" instead of primal sources, or...
And Kpp'Ar is a dark mage, and so is Claudia (in-training at this point), so it'd be within reason to assume this is some form of dark magic residue. But if it is... why not just call it that? Why make the distinction?
I think we can conclusively say there were at least two gifts given to humanity — the first was primal magic, and this seems to be more concrete. The second, assumedly, was dark magic at least in some form. But what if it was also more than that? I've talked before that as the Key of Aaravos seemingly functions now, it'd be most useful to a dark mage for categorizing spell parts/ingredients. The premonition dreams and weird blood connections between Star (Deep?) and dark magic are well known by now, even just looking at the sheer weirdness of whatever the fuck is going on with Ziard-Viren's relic staff.
The Midnight Star poem also does not help us much in figuring out the distinction between them, at least not at first glance.
Elarion, searing white, Embraced the great one’s night-black flame. And when she bowed, Her faith avowed, He whispered, “Aaravos,” his name.
Here, we get the dark-light motif pretty plainly. Fire fits with the primal flames that we're pretty sure humanity already had at this point, but we're not 100% sure. "Searing white" seems to match up with Aaravos' key, which could both relate to primal, dark, and deep magic all pretty easily.
And giving humans deep magic isn't necessarily all bad. Elarion is called "a beautiful white city" nestled in the mountains (Tales of Xadia). Leola's Last Wish star is a beautiful guiding light. This is probably the closest to a straightforward "this is when humans got primal magic or deep magic ('good' variant)" we can read into the poem, except...
It's immediately troubled by this implication and the following stanza (said connection between 2x06 and TOX found by @its-leethee).
The process marks its wielder, too: years of dark magic leave mages with pale complexions, bruise-like blemishes across the body, and blackened eyes. For better or for worse, dark magic became the key that unlocked a place of power in Xadia for all of humanity.
The closing stanza of the poem is why we all thought dark magic post-S2, for obvious reasons:
Elarion, black-eyed child, her twisted roots spread deep and far, The humans’ might sparked by the light of Aaravos, her midnight star.
Black eyes are found in dark magic use, twisted roots don't have a particularly good connotation, and we know thanks to S1 and S3 that many humans considered dark magic to make them powerful and level the playing field. Thus, the timeline would look something like this:
Elarion / humans eventually found primal magic (thanks to Leola + potentially others like Aaravos)
This drew the anger of the Stars/First elves and the dragons
Elarion asks the stars for help against the dragons, but they leave/reject it
Aaravos gives the humans deep magic (or something along those lines) through his cube ("searing white") which may or may not contain his chest piece / a quasar diamond
Through the cube, humans discovered/developed dark magic, thus "unlocking a place of great power"
