Sonnie's backstory was not explored in her episode, only that after brutally tortured and left for dead by several estate men, her consciousness was moved to her beast Khanivore by her friends. Although her human body subsequently became brain-dead as result, Sonnie can still control it through a chip which links both bodies, a control which is an inversion to her rivals who guide their respective beast in duels. This allows her to keep her rivals in the dark about her fate.
- Sonnie's mascot is a snake, as shown by her light-up tattoos, her team's hologram in the arena, and the snake icon in the episode's opening sequence.
- In the book version, it is revealed that her colleagues transplanted her brain after she crashed their van and they made up the estate men story to hide her edge.