As ancient as the abyss and a hoarder of secrets. Currently imprisoned by Bel and syphoned for information. The Sybriex knows the location of the Bleeding Citadel and how to open Tiamat's puzzle box. It knows how to free Gargauth and that Gargauth resides in the shield. It wishes to reset the leadership of Avernus and to be free from its bonds and torment.