Cassandra de Rolo

Cassandra Johanna Von Musel Klossowski de Rolo is sister to Vox Machina member Percy. She is the youngest of seven siblings. As an NPC, she is portrayed by DM Matthew Mercer.

Excerpt from Percy's Intro
"One day, a mysterious couple, named Lord and Lady Briarwood, came to the court. During a feast held in their honour, the Briarwoods violently took control of the castle, killing or imprisoning everyone who would stand in their way.  Percy awoke chained in the dungeon, only to be freed by his younger sister.  Together, they fled, chased by the Briarwoods' men.  As they ran, Percy's sister took several arrows to the chest and fell."