Quote Originally Posted by Roxas33150 View Post
Four fiends name are italian (i think) scarmignlionne, cagnazzo, rubicante and barbariccia so i think (maybe) that lyrics might be in latin or italian maybe ^^ cause i maybe hear some latin or italian words
The Four Fiends have names of the demons of the Malebranche from Dante's Divine Comedy. (Fun fact: the same is true of Calcabrina and Grafficane!)

I'm like 99% sure the lyrics to Rubicante's version of the fight are fancy-sounding nonsense, personally. But worth saying that on Twitter, Soken seemed to coyly hint at the fact that we don't know the song credits for that song, so it might not just be based on Hyadain's version.