Source: The Infernal Syndrome, pg(s). 66
The gelugon Voulgarghas helped the founder of the Hellknights, Lictor Daidian Ruel, search for information on retrieving his son's soul from Avernus, the first circle of Hell. The ice devil thereby drew Daidian deeper into corruption and strengthened infernal influence over the entire organization.
The Hellknights remain ignorant of Daidian's fate, and while many Hellknight signifers summon Voulgarghas out of the accurate belief that the ice devil knows Ruel's fate, Voulgarghas has continued to keep it secret.
- F. Wesley Schneider. (2009). Path of the Hellknight. The Infernal Syndrome, p. 66. Paizo Publishing, LLC. ISBN 978-1-60125-198-5
- F. Wesley Schneider and Jerome Virnich. (2015). Hell Unleashed, p. 3. Paizo Inc. ISBN 978-1-60125-757-4. This source is presented as an in-universe letter written by Vanchient Lor and might be unreliable.
- F. Wesley Schneider and Jerome Virnich. (2015). Hell Unleashed, p. 44. Paizo Inc. ISBN 978-1-60125-757-4