Ryuunish (リューン語)

This is an attempt at reconstructing Ryuunish from Higurashi no Naku Koro ni's Kotohogushi-hen. This page may contain spoilers for Kotohogushi-hen and the rest of Higurashi.
Kotohogushi-hen may be installed and read here thanks to 07th-mod.

Summaries

The following links contain condensed but complete descriptions for various aspects of Ryuunish, without the discussion and reasoning on this page.

Phonology/tactics Romanization Grammar

Given vocabulary

Hai: Name for the sixteen big Ryuun families
Ryuun: Name of their species
Yeasomul: Hanyuu's given name (likely means feather or wing of a bird)
Jedha: Hanyuu's family name (many share this family name)
Shezhen: Given name of another Ryuun.
Putus: Ryuuns who kept their bodies after transferring. Lit. Pure bloods
Lynos: Control Gate. An interdimensional gateway between the Ryuun world and ours.
Clossus: Likely means "law" or similar. "in accordance with Ryuun Clossus regulation #35"
Grifys: Lit. Half-blood. Created when dissociated Ryuun attempts to assimilate Human.
Ohc: link (noun?)
Ohca: one who links (linker)
Turuy Galkia: Twin Earth (referring to a sword form)
Turus Luva: Type 2
Turuy Galkia Westiabis Twin Earth Slice
Hai-Ryuun Yeasomul Jedha some part of this means "feathers of the bird wings"

-a (suffix): "one who X", equivalent to -er in english, in the case of "ohca".

All of the above words and phrases are unambiguously defined in Kotohogushi-hen.
From here, we can make a few inferences about Ryuunish. The most obvious ones are the meanings of "Turuy", "Turus", "Galkia", "Luva" and "Westiabis". We can also infer that "Turu" is the base form of the number 2, and "-y" inflects for the multiplier while "-s" inflects for ordinals.
I would also like to argue that "Yeasomul" on its own means wing or feather. The original Japanese uses "名", which may be used to refer to first name only, but can refer to the full name as well. More importantly, Hanyuu states that her name means "feathers or wings of the bird", so the part of her name which carries that meaning should at least contain Yeasomul. We also have fairly concrete meanings for Hai and Ryuun that don't really align with the definition of Hanyuu's name. "feathers or wings of a bird" is simple enough concept that should only warrant one word, and given the number of other Jedhas, it's hard to imagine they're all named after bird parts, or things carrying wings, so Jedha is likely not part of the definition. Therefore, we can deduce that Yeasomul alone means "feathers or wings".
Given these new revelations, we can make note of some more definitions.

Turu: Two
Luva: Type
Galkia Twin Earth Slice
Westiabis: Slice (sword form)(cutting through cloth??? (裂帛))
Yeasomul: Feather or Wing

-y (suffix): numerical multiplier suffix
-s (suffix): numeric ordinal suffix

As far as I am aware, this is all the vocabulary and grammar which is provided, leaving me at liberty to make up the rest as I please.
However, in order to do that, we must work out the rest of the rules for Ryuunish.

Phonology

For this part, everything will be done in ipa. Wikipedia has very convenient Consonant and Vowel charts.
You have no idea how much of a godsend the name "Hai-Ryuun Yeasomul Jedha" is. It has 5-6 vowels, giving an almost complete vowel inventory, as well as demonstrating vowel lengthening.
From this name alone, we can extract /a/, /e/, /o/ and /u/, as well as lengthened /e/ and /u/. I have made the choice to extract the second u of Yeasomul as /ʌ/, as such a pronunciation is consistent with kanafied loan words, and is much more aesthetically pleasing (kanafied it would be /a/). /i/ is also present in Hai, but it stands alone more strongly in Westiabis.
For the second i in Westiabis, and for both vowels in Grifys, it makes much more sense to extract /ɪ/, or some similar close central vowel, as Greefees sounds stupid.
I haven't found a case to extract any other vowels from the given pronunciations, and the seven identified provide a fairly balanced vowel inventory, so going forwards, I will assume Ryuunish to have the following vowel inventory

Front Central Back
Close ɪ i u uː
Mid e eː o oː
Open a aː ʌ
Diphthongs: ai, ui, (maybe more, idk)

I have made a choice to add a lengthened a and e, even though they do not exist in the given vocabulary as they are quite comfortable to lengthen. The remaining three are rather uncomfortable to lengthen. This vowel inventory could probably use a lot of refinement by someone who's better at this than I am, I'm just going to ignore rounding and assume Ryuunish doesn't split up its vowels with that.
The original transcription was in Japanese, with only five vowels, yet we have ended up with seven. Merely by the existence of Hai-Ryuun Yeasomul Jedha, this level of magic is possible for I, the Witch of Linguistics. What do you think, everyone?

Onto the consonants!
I have chosen to differentiate r and l, for aesthetic reasons in Grifys and Yeasomul. Yeasomul is originally written with ru, consistent with how /l/ is transcribed into Japanese. Grifys with /l/ sounds stupid, and when I feel it out, it wants to become an approximant rather than a flap, so I'm going to say it's /ɻ/.
Shezhen contains the /dz/ affricate, and as such I will add the unvoiced /ts/ for balance.
I am unsure whether I want to add the glotttal stop, but I probably don't.
All other consonants in the following table are present in the existing words.

Labial Coronal Postalveolar Dorsal Glottal
Nasal m n
Plosive p b t d k g
Fricative f v s z ʃ ʒ h
Affricate ts dz
Approximant w l ɹ j (w)

Some consonants may also be geminated, such as in Clossus. Making up rules, I'm going to say that all plosives can be geminated, as well as unvoiced fricatives. Not sure on whether nasals can (DECIDE THIS).
Ideas:
/ɹ/ becomes postalveolar /ɾ/ when initial (NAH)
Palatalization is followed by a rising tone.
May want to cut /ts/ (NAH)

Phonotactics

Here I'm just going to piece everything together as completely as I can based off the existing vocabulary (C)(C)V(C)(C?) syllable structure. I am unsure about the second coda consonant, it's never used, in the existing vocabulary, but if -s is the ordinal suffix and there exists a consonant ending numeral, it will be needed. However, it could be possible that the ordinal suffix is actually -is (or some other vowel), and the vowel is dropped when the root already ends in a vowel. I believe this is a creative decision that can be left to future me. I personally like the idea of only one coda consonant.
Making up rules, the coda should not contain a /w/, /j/ or /h/, for ease of pronunciation. Ryuunish should sound somewhat noble and powerful, and awkward phoneme combinations don't really help that.
Should follow sonority hierarchy.

Further phonotactics left for later.

TODO

Finish phonotactics
Unambiguous romanization
Accent/Stress
Construct grammar
Construct vocabulary
Oh boy that's a lot of stuff I get to make up.