With the game having a large cast and the recurring habit of Vyrn in giving them nicknames, this list acts as a compilation of the in-universe nicknames that he gives to the cast. The entries are divided into two using a slash - the official English translation of the nickname on the left, and its Japanese pronunciation on the right. Though there are other characters aside from Vyrn who also give nicknames to a selected few.
Nicknames given by Vyrn
- Ange - Big Hat
- Anthuria - Fire Girl
- Attiyah - Mustache Mister
- Azazel - Ashes
- Barawa - Chairlock Holmesnote
- Beatrix - Blue / Ao-nee-chan
- Cailana - Surfer Girl
- Carmelina - Hoops
- C.C. - Pizza Girl / Pizza nee-chan
- Cucouroux - Miss Gunsmith
- Ejaeli - Metal Mask
- Eustace - Sourpuss
- Ezecrain - Mr. No-Brows, and Browless Wonder
- Friday - Miss Batter-for-Brains / Ebi Furai no-nee-chan
- Grea - Pianista / Piano no-nee-chan
- Ilsa - Scary Lady
- Isaac - Four-Eyes
- Izmir - Winter Wondergirl
- Izuminokami - Coatster
- J.J. - Hip-Hop Head
- Johann - Mr. Scholar
- Karyl - Whiskers / Nekomimi no-neechan.
- Kokkoro - Lordette
- Kumbhira - Kumboara
- Lobelia - Conchy
- Lucio - Spangles / Kira-kira nii-chan
- Maria Theresa - Lady Assessment
- Medusa - Snake Girl
- Melissabelle - Goldilocks
- Metera - Ms. Shameless
- Mikasa - Scarf Girl
- Narmaya - Butterfly Girl / Chou nee-chan
- Nicholas - Mecha-Nick
- Niyon - Harp Girl / Koto nee-chan
- Pecorine - Miss Peckish
- Percival - Sir Burnsalot / Tosaka no nii-chan
- Ran Mori - Karate Girl
- Raybury - Junkbot
- Razia - Scrappy
- Rei - Ms. Eyeballs
- Rick - Detective Bungler
- Sandalphon - Sandals / Sandalo, Grumplephon and Queasyphon
- Seox - Masked Wonder / Kamen manto no nii-chan
- Sevilbarra - Straw Hat Guy
- Shao - Medicine Man
- Sierokarte - Knickknack Lady
- Silva - Snipes
- Skull - Crossbones
- Spinnah - Fidget Fingers
- Tanya - Knife Girl / Knife-no-neechan
- Tien - Gun Girl
- Tsurumaru - Silverlocks
- Tyre - Clefty
- Vanzza - Tonfa Bro / Tonfa-no-nii-chan
- Vaseraga - Spiky
- Yamanbagiri - Hoodie
- Yuisis - Crazy Girl
- Zaja - Slouchy
- Zeta - Red / Akai nee-chan
- Zooey - Miss Flippy-hair
Nicknames given by other characters
- Aglovale - Aggy (by Lamorak)
- Albert - Old Man Sparky (by a little girl)
- Alliah - Ally (by the Captain)
- Andira - Andy / Anchira-chan (by Kumbhira)
- Anthuria - Anthy (by Chloe)
- Arriet - Ettie (by Lyria)
- Arulumaya - Maya (by the Lowain trio)
- Azrael and Israfel - Az and Iss (by Halluel and Malluel)
- Baal - Baally / Baru-kun (by Satyr)
- Beatrix - Hellcat (by Ilsa), Northsister (by Odajumoki Ruffians in "Gripping Freedom"), Miss Witch (by children in her Halloween episode)
- Beelzebub - Bubs / Bab-san (by Belial)
- Belial - Beli / Beli-san (by Tomoi)
- Cailana - Caily (by Chloe)
- Camieux - Cammy / Kumubo (by Cucouroux)
- The Captain (Gran or Djeeta) - Bloodkin / Kenzoku (by Vania)
- Christina - Christy, or Lady Christy / Kurisu (by some staff and members of the Jewel Resort Casino)
- Constance - Connie (by a thug in The Maids' Fate Episode)
- Cucouroux - Coux (by Camieux)
- De La Fille - Fille (by Therese)
- Drang - Drango / Durachi (by Lowain and his bros.)
- Ejaeli - Eji (by Lowain)
- Elsam - Sammy (by Lowain)
- Eustace - Eusless (also by Ilsa)
- Felluca - Lulu (by her sisters Nemone and Melleau)
- Freesia - Freezie / Fu-chan (by Tomoi)
- Hallessena - Hallie (by the captain, Vyrn and some thugs)
- Halluel and Malluel - Hal and Mal (by Lyria)
- Izmir - Izzy (by Carren)
- Jasmine - Turquoise, and Tiger's Eye (by Walder)
- Korwa - Korwie (by the Lowain trio)
- Kumbhira - Kumbhi / Kuvira-neechan (by Andira)
- Lamretta - Lambo (by the Lowain trio)
- Lancelot - Lancey (by Vane and Elsam)
- Leona - Leo (by Cain)
- Lucio - Poopie / Poopio (by Azrael)
- Lucilius - Cilius / Fa-sannote (by Belial)
- Lucifer - Fluffy Feathers (by Lyria in her skill fate), Cifer / Fer-san (by Tomoi)
- Lunalu - Luna-rad (by the Lowain trio)
- Lyria - Sapphire (by Walder), Lyrina (by Chloe)
- Mahira - Maki (by Andira)
- Medusa - Medussy / Medu-chan (by Satyr)
- Michael - Mikey / Mika-chan (by Belial)
- Milleore - Milly (by Sahli Lao)
- Mimlemel - Mim (by Vyrn, Lyria and Selfira)
- Morax - Moo Moo (by Magisa)
- Mordecai - Morty / Mort-chan (by Luna)
- Nezha - Nez (by Satyr)
- Orchid - Original (by Zwei)
- Percival - Perci-smell (by Isabella), Percy (by Lamorak)
- Pommern - Pommy / Pomme (by Lowain and his bros.), Major Mustache (by Io)
- Rackam - Racky Rack (by Pengy)
- Raphael - Windy (by Cagliostro)
- Reinhardtzar - Tzar (by Cain)
- Robertina - Tina (by the other members of the Sky Philharmonic Orchestra)
- Rosamia - Rosa (by Chloe)
- Rosine - Rose (by her husband Florus)
- Sandalphon - Sandy / San-chan (by Belialnote , Malluel, Lucio and Azraelnote ), San / San-kun (By Israfel)
- Sariel - Sarry (by Belial), Sarrybear / Sarryto (by Azrael)
- Scathacha - Scathy (by Lowain and his bros.)
- Tomoi - Tommy (by Lowain)
- Tyre - Ty / Ta-kun (by Lowain)
- Ulamnuran - Ulam / Urocchi (by Carmelina)
- Vajra - Rara / Vajjy (by Andira)
- Vaseraga - Armored Chicken (by Ilsa)
- Vyrn - Vyrnathan (by Chloe), Lizzie (by Vania), B (by Tsubasa), Ruby (by Walder), Scaly (by Belial)
- Walder - Wald / Weru (by Lowain and his bros.)
- Walfried - Blue (by Dante)
- Yggdrasil - Yggy / Yuguyugu, or Yugugu (by Elsam)
- Zeta - Pupper (by Ilsa)
