Tokki is a ghost in the Destiny universe. Ghosts are companions of the player. In this story, Tokki was aboard a space station, using unknown technology as an accessory to her shell. The Exo Stranger/Elsie Bray stumbled upon Tokki and the tech, and is now studying it. Tokki could be described as innocent, oblivious, and youthful. She doesn't really see the point in the research Elsie is performing, and doesn't want to be stuck in a lab. This character hasn't appeared in-game yet, so there's no frame of reference for how she would sound.