Questions About Archaic Japanese


I recently came across this song that I really like, 「神居謡{かむいよう}」.  
(Link to the full lyrics
[here](https://www5.atwiki.jp/hmiku/pages/18511.html).)  
This sparked a few questions about archaic Japanese, which I know little of.  
How would you translate 「神居謡」 anyway? "Kamuy Chant"? "Kamuy Hymn"?

In any case, I'm fairly sure that I understand the meaning of 「～ねど」, 「夢む」, and
「萌ゆ」.  
What perplexes me is the usage of 「や」 in this context. I can guess, but that
doesn't really help.  
Also, I wonder if there are other usages of archaic Japanese here that I am
misinterpreting in a modern context.

The other thing that I wonder about is the usage of 「君」. Did it mean something
different than what it means now?  
The reason that I ask is because I know a handful of Chinese vocabulary. As we
know, kanji is borrowed from Chinese, with some things staying as is, and
others being altered.

The Chinese word for "you" is "你" (ni). "君" (jun) in Chinese refers more to a
lord.  
So, this leads me to wonder if 君 held a different meaning at all back then.
Its usage seems strange within the song, to me.

Spiritual and/or mythological references that I might be missing aside, it
would be nice if I fully understood the song simply on a language base.

One last thing.

> 君や君や 夢む過客や  
>  賽に玩ばれて 見失う

These two lines are doing my head in. Is it to be interpreted as saying that
the singer has lost the person in question to fate?

Sorry for asking such a difficult question. I would be overjoyed if anyone can
provide some insight on the matters at hand. If you have anything else to add
to what I have already inquired about, I would be grateful for that, too.  
Its easy enough to look up on Japanese forums the meaning of words such as
「夢む」, but when they mirror modern words, it becomes harder to source an
answer.




Concerning や, you can think of it as よ (vocative marker), and 君 just seems
normal "you" here. (Second person's pronoun usage of 君 dates back to ancient
time, though, for example, that of 君が代 seems to have originally mean the lord
of Azumi.) So, the example sentence means "You, a dreaming drifter, you were
mocked by dice and at a loss".

p.s I interpret 古き魚 波に躍る as "an ancient fish drifts on waves" unlike the
translation in the video.

