Thanks to Nosys from Furaffinity for the question!
There are a ton of proper nouns in the DragonScape lore, Õndem, Mavõtur, Éldimor, and not all of them, but a lot of them have some sort of tilde or accent (~ or ‘) and the comics never have really gotten much into the phonetic rules of these words or pronunciations.
So where do these all come from?
These words all come from an in lore language that is known as Éla which is the language of the Sivilão (the teal steels in the comics) who are, much like humanity, a vast diaspora scattered across the endless skies of the Celeste and the myriad planar within. At the time of Imuas arrival into the DragonScape Éla could be more usefully thought of as a language family more than any one language, with a myriad of dialects and even descent languages of éla appearing all over. All of the proper words of the DragonScape are derived from éla. Words like Drekir, Ormer, Skrimír, Õfuthar, amongst many other words are all éla words (hence why Imua wouldn’t be familiar with the fact that her species is known as the Drekir).
Time for a phonetics lesson!
At least for answering the question! So gonna focus on a few select things that may not sound like how we may expect!
So Ã, É, Í, Õ, Ú, as well as L, and your Rs! That said, its important to point out that a lot of Éla utilizes vocalizations such as rattles, yaps, clicks and whirs that we cannot really replicate as humans! So things like Ls and Rs are less literal phonemes and more representative of draconic vocalizations. But lets start with the ‘Yohn’ vowels! Unfortuneately WordPress will not let me post audiofiles. if I could i would record these things but in the mean time I do as best I can with writing.
Whenever you see something drifting over a vowel, such as õleduradir (Blessed voices unheard) or a simple word like ãel (yes, greetings, etc.), you simply say it with a “yuh”, a Y.
So for example, ãel is said simply as a Yuaelkch or Yaelkch
whereas õleduradir is said as Yuolkch-eh-doo-r-adi-r
This also applies equally to vowels with accent marks, as it’s more just a weakness of the international keyboard that cannot type an I with a Tilde.
So for example, Skrimír is said as Sk-r-eem-yueer
likewise, a word like Gulémgão is said as Gukch-yuem-giyuao
For dragons this is created by a flex deep in their throat, making a very deep “yuh”, perhaps in a sound not too far separated from the deep throaty “yump” sounds of ostriches… though for drekir certainly slightly higher pitched, and for ormer absolutely far deeper a tone. But for us large monkeys, a “yuh” is about the best I feel we can do.
Now while that was the question I do want to also elaborate on the “L” and “R” as those are also not necessarily said how they are written, just more as representative placeholders for vocalizations.
L’s are representative of a throaty, phlegmy huff common in Éla, usually done through the mouth (as opposed to most natural huffs done through the nostrils). an L is used as the general mouth shape is similar to an L.
So a word like Sivilão is said as a See-Veel-kchiyao with an L that is less said and more shaped.
And lastly Rs, which are more just representative of rattles. Rattles are important in draconic speech in general as it helps imply emotional and contextual tone and intonation for dragons and is something you see even amongst dragons speaking human languages. For Éla it is considered so important that many words will allow for rattling, particularly to imply plurality, though is also employed for a variety of other contexts.
Taking a good word like Radir (voices), it is really said a lot more as (rattle) adi (rattle) with those rattles helping establish tone. If you want to say them as a human I would recommend rolling your r, like a spanish erre though with the tongue further back into the throat. Takes a bit of practice, may sound weird, but as far as I know humans cannot emit a crocodilian rattle.
Hope that helps! Thanks for Asking