Very little is known about Bryseis Kakistos other than she was the leader of the Toril thirteen, the original thirteen tiefling warlocks who made pacts with Asmodeus. She was said by the cambion Lorcan to have been a thoroughly wicked person who was partially responsible for Asmodeus' ascension to godhood. She lived near Vaasa and was alive in the 14th century.
- Brimstone Angels (2011)
- Brimstone Angels: Lesser Evils (2012)
- The Adversary (2013)
- Fire in the Blood (2014)
- Ashes of the Tyrant (2015)