Lavender (Lavi) Chance is Olive's sister and the current Saint Candidate of Aries, the current Saint of Ashes.
When Lavi and Olive were younger, Lavi was discovered to be a potential Saint Candidate and was taken to Ophiuchus, where they ran tests she was said to have failed. Shortly after she became a failed Saint Candidate, the Tragedy of Aries occurred, leading to Lavi and her parents' demise.
After her death, she was still visible to her brother, leading him to believe that he was insane. But later it was discovered that she is visible to both Olive and the rest of the Six, her vitae replacing Shion's in their True Conductor circle.
Meeting the Six
Lavi participates in their weekly check-in meetings, and gets along with them very well. Maria is shown to tell her stories about Maria's adventures abroad and Lavi is fond of all of them.
Lavi is very protective of her brother, and worries about Olive quite a lot as shown after Olive nearly get assassinated. She is a very caring person. She also appears to be slightly air-headed, but this may be a result of her only being able to come up partially above the Threshold.
When Werner encounters her at the Threshold, she is shown to be very serious and blunt.