From what I can tell, it sounds very similar to Gaelic. Now, mind you, I don't speak Gaelic...or Swedish......or any other language that you mentioned, but just from listening to it, and trying to find other songs that sound similar to it, Gaelic is what seemed the closest to me.
What's interesting about this though is that there are some words spoken in English, or at least pronounced in a very similar way. "Dells" in the second line, and "belies" in the tenth line are the most noticeable. However, I was also able to pick up "soon", possibly "fathomless" (this is one of the harder ones), "frozen" but it sounds like "fresen", "time", "tone", "hand" but said as if the person has a German accent (if that makes sense), possibly "fallen" (another tough one), and finally "mountainsmith" in the last line but said like "mantinsmih".
This actually leads me to believe that Ancient Freljordian is structured exactly like English, which, if you think about it, makes sense. When developing a language for a fictional world, it would be all too easy to structure it just like the one you speak, but cover up the structure with the pronunciation of the words. Only the people who pay really good attention, and those who actually built the language, would have any clue as to how it is structured.
Well, Riot, sorry, but I paid attention! I don't know if any of the languages you listed are structured similarly to English, but, that's what I've been able to gather.
Forget everything I said there. I went into Google translate trying to find a language it best matches, and Danish is actually a very close fit. There are some differences, but God damn is it similar.
