|Casty Rianoite (Cass)|
|Kanji/Kana||キャスティ・リアノイト (Casty Rianoite)|
|First Appearance||Ciel nosurge: Ushinawareta Hoshi e Sasagu Uta|
|English Voice Actor||Stephanie Sheh|
|Japanese Voice Actor||Inori Minase|
- Duo Waltz of the Rainbow Country : A song sung by Cass to help Nero escape from Tenmon, as well as to help herself and Sarly flee from Palace Nyurokeel. This particular kind of Song Magic requires powerful feelings, and imagination in order for it to manifest anything into the world, because Cass was so very focused on saving Nero, it allowed her to sing the song with success.
- Class::CIEL_N_PROTECTA; : This song serves the purpose of protecting the whole of the Colony Ship Soreil and its main Song Magic library. When this song is sung, a support system called the CAHS sings alongside the singer, allowing for the singer to deliver simple commands that the AI of the system will interpret and take care of the rest.
- Class::EXPAJA; : A song created for the sole purpose of making it impossible for the Maternal Overseer to form, however, because that became an impossibility, it continued to exist for one reason in the aftermath, weakening it. Initially, this song was supposed to be sung by Ion, but due to circumstances, that was riddled impossible too--and thus Earthes had to download this song into Casty.
- Class::AR_NOSURGE#RE:Incarnation; : A version of the Cieln Class::AR_NOSURGE; that exists to access the mind of a person who has Interdimend installed, and to exert control over it. Cass sung this song in order to reconnect Delta's Interdimend, initially she was unwilling to do so. But after everyone spoke to her about the matter, including Delta himself, and even Ion offering to sing the song, Cass understood it needed to be done. Following singing the song, Cass reach out to the player themselves to save their world as soon as possible.
- Ar-ciel Ar-manaf : Created by the Seven Chaining with each other, this song is one which holds a very powerful effect--it forces the souls of Ion and Nero to take on the same composition as those native to the EXA_PICO universe. It also permanently severs them from their original worlds. It serves as the ending theme to the game in all endings sans the bad and true endings.