I’ve been percolating another thought about these, and in particular their possible Ritual roles and/or implications.
This one comes from the unsettled debate in the stories regarding the Body/Spirit/Soul and what is The Self. These are mirroring some of the classic arguments surrounding the philosophic questions of Life and The Self. In my metaphysics classes all individual definitions seemed to fall short, but something I was always fascinated by was the Egyptian Idea of self, which sidestepped the issue by defining no less than 5 parts of the self, in addition to the Body, each with a different purpose. I see some similarities with these artifacts, and the DV idea of the Self.
https://en.wikipedia.org/wiki/Ancient_Egyptian_concept_of_the_soulSo the parts are: the Ren (Name), the Ba (Personality), the Ka (Vital Spark), the Sheut (Shadow), and the Ib (Heart's Blood). My thought is that each Artifact was intended to Bind a specific part of that complex Self.
The Placard Binds the Name/Ren. You know, with Magic.
The Ka is the Vital Spark, "What makes them Alive", and Death is defined as it leaving the body. This fits Magic/Life most in the DV, I think, so Ill say that the Crown of Thorns restrains it like Thorned Manacles for mortal magic. It is sometimes identified with a "Spirit" from other religions, but there were cultural complications there (Egyptians didnt really conceive of a non-corporeal afterlife).
The Bah is the personality, and by the description I think fits best the DV idea of the Spirit/Ghost.
The Sheut (Shadow), doesnt have much in the way of specific purpose that I can find, it was more that it was observed, ever-present and obviously connected to the very significant Sun, so it was given high status. Best I can find is that it is "The mark one leaves on the World". Not sure here, but the physical imprint on the Shroud has a sort of Shadow feel to it...
The Ib is the Heart, or Heart's Blood. It is the seat of emotion, will and intention. It is "a metaphysical heart was believed to be formed from one drop of blood from the child's mother's heart, taken at conception." It is what is Judged in the afterlife, what bears the marks of your good and evil deeds. This sounds like what is popularly called a Soul in the DV. Im gunna say for now that the Spear binds the Soul, by literally piercing the physical Heart and stealing that Drop.
Further, the Ka and Bah were supposed to leave the Body and reunite "On the Other Side" and become an Akh, whose definition varied widely over the dynasties, but mirrors the Spirit+Soul metamorphosis that Bob alluded to (but said he didn’t really understand) in GS.
So in this, each artifact was intended to Bind a particular aspect of the Self:
Placard = Name
Crown = Life Magic
Cup = Personality/Spirit (?)
Shroud = Shadow (?)
Spear = Soul (?)
Separately there are also the Nails that restrain the Body in a more literal way, so:
Nails = ha/Body
(Edited to correct old typo's that still bothered me)