The Wuxing Elements in Relation to Eye Colors in Mononoke
Universally across all cultures, eyes are windows to the soul, yes?
Spoilers regarding to the analysis of new lore below the cut:
Wuxing, or 五行 in Chinese, translates literally "five movements" refers to the interactions between the five elements of wood, fire, earth, metal, and water. The methods of I Ching divinations with its complex bagua (八卦) trigrams and hexagrams build its foundations upon these movements. Here's the diagram illustrating how the elements relate to one another:
Let's examine the wuxing diagram, specifically the color its elements corresponding to the eye colors of Anime-Kusu, Hyper, Movie-Kusu, and Shingi.
Anime-Kusu's eyes are blue, which aligns with 木 - wood. It has a symbiotic generative cycle - 相生 - with 火 - fire, which aligns with Hyper's eye color. The simple metaphor here is that you cannot create fire without wood to kindle it. This makes sense, since Hyper's form is modeled after Kusu.
However, if this relation is left unchecked, it can become a destructive reverse-generative cycle - 相洩/相泄 - where wood is burned by fire. The fire-aligned exorcism sword Ri/Li - 離- serves as both bridge and barrier between Anime-Kusu and Hyper. Hyper's fire element feeds on Kusu's wood element, but can only be released under specific conditions (the exorcism ritual).
Movie-Kusu's eyes are yellow, which aligns with earth - 土. Similar to above, earth has a generative cycle with metal - 金, which, what do you know? Aligns with Shingi's white eye color! The earth-aligned sword Kun - 坤- serves as an intermediary between the two of them. Interesting, right? :D
Now let's to delve into headcanon territory that anime-Kusu and movie-Kusu have a mentor-mentee relationship. Anime-Kusu could have an inter-regulating relationship with movie-Kusu where wood stabilizes earth (thus preventing it from eroding).
Alternatively, if they are somehow at odds with each other, earth can also rot wood. From a meta level, this could represent how Kamiya replaced Sakurai as movie-Kusu's voice actor. Ouch.
We actually see a similar relationship between Hyper and Shingi, in which fire (Hyper) refines/shapes metal (Shingi).
There's an added complexity where Hyper's pupils are uniquely gold/yellow, which may give him an even deeper connection with metal-aligned Shingi because gold technically a metal and 金 also means gold in Chinese. Since they are divine beings, I think it's appropriate they have this level of depth in their relationship.
(Hyper's pupil color can also be interpreted as yellow, which matches earth-aligned movie-Kusu with his yellow irises!)
Another common thread between the two divine beings is that their sclera are both black, which represents water - 水. Water dampens/regulates fire (Hyper) and rusts metal (Shingi).
I believe this represents the represents the exorcism sword's power to confine/limit both Hyper and Shingi's powers until the time comes to unleash them. This is visually symbolized by the black schlera surrounding/containing their colored irises.
Shingi seems to have the shorter end of the stick since metal corrosion is a more potent type of destruction, which may explain his more human-like appearance compared to Hyper's otherworldly one. That...probably doesn't bode well with his upcoming battle with the karakasa.
Update: created some infographics based on the above post so I could share it more easily on Twitter.
My enthusiasm for Mononoke is breaking confinement from Tumblr...
