As usual thanks for the summary guys.
Maybe not a very welcoming type of remark lately, but I can't help but get some strong norse mythology vibes from this episode.
It seems like the World Tree was always a thing and that the spiritual trees were just keeping it contained and the astral world at bay. Witches like Flora were guardians, who also harnassed the strange properties of it into magic, like some type of nature magic based Scientists. Pretty cool actually, and it explains why magic users are so rare; they apparently can only be found near these trees, because the trees influence their power and knowledge of magic.
Your comment as well as the description of the guardian witches and magic users carrying research in the forests of spirit tree (that seem to have a parasitic relationship with the World Tree branches) reminded me a bit of Odin's episode to seek the knowledge and powers of the magical runes at the branches of Yggdrasil. The resemblance is more on an aesthetic-conceptual level (the purposes and of course the ordeal of the tale being quite different), but I find it interesting enough to be worth mentioning.
Also regarding that point, I was re-reading some parts of Volume 24 in the last few days after reading episode 344, and with the assumption (now confirmed) that Flora was one such guardian of one of those forests of spiritual trees, it striked me how she felt responsible for the ongoing events at that point (appearance of trolls into the corporeal world): case in point, even before addressing Guts party, she made sure to prioritise Morgan's story. She couldn't fix the issue by herself, so she had to delegate the task to Schierke as her student and even making a bargain with Guts (in exchange for the talismans) for them to help her. Given her illustrated role in this episode, I found that very consistent and interesting to put in perspective.
The other element in this episode that gave me a Norse mythos vibe, even though I might be reaching a bit more with this one, is the naming used to addresss this sort of phenomenom: "road of dragons" going by the summary. Surely it's looking more metaphorical than anything right now, but given some of the story connections being made with the World Tree and the vortex and/or abyss, and having in mind the parallel with Yggdrasil, the World Tree of nordic mythology, I can't help but remind of the dragon-serpent that lives gnawing at the bottom of its roots, Nidhogg. I'm sure this isn't particularly new either, but as it's a new (and very curious) term from this episode and given the vibes I was getting, I found it too interesting to leave unmentioned.
Relating to these new described phenomenoms in this episode, "road of dragons" and "road of elves", I'm reminded of another episode I happened to have covered in my selective re-read: episode 177 - "The Rent World" going by DH's edition. We see a situation that seems much similar, if not the phenomenom itself being illustrated when the kids notice how the forest they were so familiar with started to look or feel different/strange as of late. Although the scene didn't involve a night of moonlight (there seemed to still have broad daylight in the scene, covered by large dark clouds), I assume the corresponding trigger to its occurrence was Griffith/Femto's appearance and how that also affected the world, as he actually happened to just pass/fly by the kids in the forest at the back of Zodd. Actually that there was broad daylight to be seen probably reinforces the point of how much his coming to the corporeal world affected the balance. Later in that scene, we see what seems to be an elf folk in the tree opening, much like it's illustrated in this episode.
As for other impressions, I think it's nice and interesting to see what seems to be (or at least so far portrayed as) a young adult in Danan at the place, it's something I saw people thought about in the previous episode thread since all we saw were mostly kids in the island so far. And I love the way Morda has been just laying there in the sidelines, relaxed and just listening to all this important discussion with her face half covered by her hat. Looks pretty badass and reminds me a bit of the demeanor of young Guts in a way (mercenary/Band of the Falcon Guts, just feels like something he would do).
Well, right now I just can't wait to get a good read of a reliable translation for this episode. Reading these nice bits concerning the world building and letting them sink in, have my take on it and see how else they expand what else we know.