From an interview with Tabata, Nomura, and Kitase in the Final Fantasy Type-0 Ultimania, p.839...
Were you the one who came up with the characters' names this time, Nomura-san?
Nomura: Chiba (the lead scenario writer) was the one who came up with Machina and Rem's names, but I was the one who came up with the names for the rest of Class Zero. I wanted to make them sound like codenames, and when I was looking for a cohesive set of 13, I came upon the names of playing cards. Because "Joker" sounded so enigmatic to me, I thought "This'll be good." I had already drawn the illustrations of the characters, so I applied the names of the cards while looking at each of their faces.
Tabata: The names of King and Nine really fit their image perfectly.
Did you come up with their weapons while you were drawing the first group illustration?
Tabata: About half of them were strange things at Nomura's request. Typically, you wouldn't think of choosing things like a flute and cards as weapons, right? (laughs)
Nomura: I caused the staff a lot of problems. They were like, "So... How do you fight with this?" I thought of it as an extension of "BC -FFVII-" where each character's weapon displayed their individuality, so I was just concerned about creating too much overlap.
Tabata: I thought "He's going to come up with something really interesting", but the staff on hand weren't familiar with Nomura's personality, so they took everything very seriously and were like, "She plays the flute? Really?"
Nomura: I was very relieved by the fact that Deuce's fighting style makes an impression. I was surprised when I first saw her in motion.
Tabata: Your strange requests became the important hurdle that helped us avoid making the content too conventional.
Outside of Class Zero, Emina is a character who made a strong impression.
Tabata: It was actually Kitase who was in charge of Emina's event.
Kitase: No, it was actually an idea the female staff members came up with, and then I just set up the camerawork. The staff who were involved had their hands full with other work, so they asked for my help. It seems the camera control was complicated in that scene, so it came around to me because I was used to it...
Tabata: The idea behind Emina's event was to "provide content that meets a wide range of tastes." (laughs) We wanted to give players a variety of camera angles so they could choose the one they liked most, but Kitase's first camera was particular to his own specific interests (laughs), so it had to be reworked.
Emina and Kazusa are connected, aren't they?
Tabata: Yes. I didn't say anything about Kazusa and let a few female staff members do what they wanted with him. I just told them to make sure that the content would "stick with players." Because of that, I feel like Emina and Kazusa became sub-characters who stayed in players' hearts.
Even the moogles were memorable this time.
Tabata: They’re cute, aren’t they? To tell you the truth, I actually prepared a scene to introduce the group of moogles known as the Cranberry Knights, but Chiba forgot to put it into the game, so now it's just a memory.
Nomura: That's a shame. As soon as I saw the moogles' designs, I even said, "We should make merch of them right away." (laughs) At the moment, I'm thinking about designing moogles for “FF Versus XIII” that are similar to the ones from “FF Type-0.”
Tabata: I was shocked when I found out that Moglin's official name is a long, foreign name. I heard that it was Nomura's idea, but...
Nomura: The scenario staff were the ones who came up with it. I was also surprised when I heard it for the first time during voice recording. If you look at “Kingdom Hearts” where I've chosen all the names myself, you can tell that I have a preference for simpler names. (laughs)
