An alien girl suffering from amnesia. She can only remember certain basic info of herself, and her brother.
Apparently she went mysteriously missing, spawning in an empty world surrounded by a dark corruptive energy.
Sonia stablished connection with a deity that was merged with such energy, eventually accidentally saving her from being consumed by this energy called the Void.
The deity's name was Meast, and they forged a deep friendship.
When Meast was able to take a physical form, she promised to help Sonia find a way back home.
Seems that most of Sonia's memories were eroded by the Void.