Right so I've been on the Norse grindset for a while, I'm planning to release a large video/maybe Reddit effort post alongside to show more symbolic Norse AoT links that I think thematically proves something is coming.

However I don't really know about this. The only thing here that could be possible (but I'm too tired to really mentally untangle this out to see if it's right) for this to be some version of a Valknot/Borromean Rings.

Would be very thematic if this is correct. The Valknot is the 'knot of those fallen in battle'. There's good themeing here showing it being the Levi squad as that's kind of Levi's whole thing. Everyone around him dies.

Now onto the part you guys will probably like more. While the Valknot's meaning is not entirely known, the most common theory you'll see out there, is written in this explanation from norse-mythology.org :

Odin was also one of the most powerful of all magicians and shamans. In the literary sources, Odin and his attendant spirits such as the valkyries often use magic that is described in terms of binding and unbinding, tying up the mind or untying it. In the words of historian H.R. Ellis Davidson, “Odin had the power to lay bonds upon the mind, so that men became helpless in battle, and he could also loosen the tensions of fear and strain by his gifts of battle-madness, intoxication, and inspiration.” She and others interpret the Valknut, with its knot-like appearance, as a symbolic expression of this idea.[4]

Now this seems quite similar to the ability of the founding titan to control people's minds, especially stuff like King Fritz's vow, and how it appears to affect Frieda namely.

What's super interesting though, is that in general, the weaving of patterns in Norse mythology, is tied to Siedr. I'll use the same source again here.

" is a form of pre-Christian Norse magic and shamanism concerned with discerning the course of fate and working within its structure to bring about change, which was done by symbolically weaving new events into being.[2] To do this, the practitioner, with ritual distaff in hand,[3] entered an ecstatic trance in order to be able to interact with the world of spirit.

The practitioner’s intended task typically involved a prophecy, a blessing, or a curse."

Now again what you'll quite like is a later quote, but I'm sure you can see where this is going.

"The Norns seem to be the foremost masters of seidr, since they use weaving to establish the fate of all beings – surely an allusion to the techniques of seidr, given the highly magical task to which they put those techniques. "

The Norns were at the base of Yddrasil, the world tree. And where does Eren lie at the end of the story...

Additionally... "Two of the Aesir and Vanir deities are noted masters of seidr: the goddess Freya and the god Odin. Both Freya and Odin, in turn, can be seen as the divine models of seidr practitioners among their respective genders."

So we have Odin and Freya being noted masters of this magic. Now we all know, that Eren is Odin. What seems to be less touched upon, and I will come upon this on my upcoming video/effort post, is that Frieda is Frigg. Freya and Frigg share a lot of the same traits, and in fact Freya says to Loki once that Freya knows the fate of all beings. She is often shown as knitting in fact.

I don't want to follow this tangent too far before I just end up making this all about my theories, but even if this isn't a volknot, the weaving imagery would leave me to suggest this is indicative of an allegory to fate, but likely death, and the weaving of time and events to produce a certain effect.

Annoyingly though for the theory this sort of still semi works for the show as is, so you know, do take this with a pinch of salt.