She is named after the Russian mythological creature of the same name which is usually depicted as a beautiful half-woman, half-bird.
In version 5.0, an ELF form of her was released. In version 6.9, she became playable with the Miracle Magical Girl Mecha/Fire battlesuit.
Sirin's personality evolves from kind and caring to power-hungry and vengeful. After her awakening, she becomes prideful and arrogant, viewing humans as insects and considering herself chosen by God. However, she still yearns for someone to believe in, which affects her attachment to Cecilia and Kiana. In her return, she becomes more composed but maintains a deep anger towards humanity.
Playable as Miracle ☆ Magical Girl, Sirin embarks on a journey to accept her immaturity and innocence, piecing her shattered heart back together.
"One step at a time. No need for impatience or hesitation. Someday, you'll discover that you've already become the person you've been yearning for."
