When Aria was nineteen and her sister eighteen they went to study at the Bangkok Institute. Aria began introducing David as Diana, allowing her be herself. One day the siblings went exploring a group of islands rumored to have demons; what they found were revenants. In the ensuing battle Aria was fatally injured and died while being treated by Catarina Loss. Diana, heartbroken, survived and assumed her sister's place after their parents falsely reported to the Clave that David had died instead of Aria.
Aria was a very accepting and understanding person. She was also very perceptive, as she was able to determine on her own that her sister was a woman, without being told.
Aria loved her brother very much and tried to help him live the life he wanted, as a woman.
- Lord of Shadows (first mention)