Sinya functioned as a bodyguard for the Black Sun criminal organization and was a Twi'lek. Although she lacked any connection to the Force, she fought with a pair of guard shotos that had perpendicular grips and emitted purple blades.
Sinya was the bodyguard for Darnada, a Vigo in the Black Sun organization, when Darth Maul eliminated the Black Sun's leadership. When Maul expressed his desire to join the criminal syndicate to the Vigo, Sinya voiced her disbelief, dismissing Maul as "nothing special". Even as he single-handedly destroyed everyone in the room, Sinya continued to mock him, referring to him as a typical assassin. Only when Maul quickly gained the upper hand did Sinya realize the gravity of the situation and express fear and uncertainty about Maul's true nature. The Sith swiftly beheaded her, leaving her unable to protect her employer as Maul impaled him through the eye. Her lightsabers were likely destroyed along with the rest of the Black Sun station.
Sinya possessed a degree of arrogance, evident in her taunting of Darth Maul during their confrontation. Darnada also noted that she was not easily impressed. Despite these qualities, she displayed fear and uncertainty as Maul gained the advantage, recognizing him as more than just an "ordinary assassin," though she did not recognize him as a Sith, unlike Mighella, another Black Sun bodyguard, who correctly identified him as a Sith Lord, while also acknowledging he was more than just a typical assassin.