Kingsglaive is a guild made by Nyx and Lunafreya (formerly Asch and Prompto, respectively) created in 2016. This guild is a French guild made exclusively for French players (mostly IRL friends) and also for (maybe) help French players.
In order to join this guild you must speak French (and love Final Fantasy, because the guild name is taken from Final Fantasy XV). This reason is because the guild is planned for French players and in order for the members to freely speak French anywhere (like a private global chat)
(and too much French :P)
Currently, there are three known members (including NyxUlric, Lunafreya and KartSeven, all of them are French players).