Seems like a machine translation, and a pretty rough one at that. Also, feels like some info is missing? When did the MC start getting referred to as the "Roaring Silver Warrior"?
Pixiv says Kuon Ginji is spelled 玖音 銀士.
Those kanji, individually mean something like
[Nine/Black jewel]-[Sound/Music] [Silver]-[Warrior]
...which means that the kanji of Argen's original name was DIRECTLY converted into literal Rnglish.
Yeah, that pretty much HAS to be a machine translation. Or, in other words, actual fucking dogshit.
I can't understand her reasoning given for refusing because the translation is so bad. Fire this "translator". Preferably, from a canon into an active volcano.