Thrice-bound daemonhost. Summoned and enslaved by Inquisitor Renthor. Engineered the near destruction of the Chains of Judgment, but was unable to free himself. Freed by Castor. Zul declined Castor's offer of expediting him back to the Warp. Centuries of being bound in human form had made him strangely attached to the material world - and his current host body.

Holds many of the late Inquisitor's secrets, including the location of Consovor and the head of the Dusk Hag. Doesn't really serve Castor; he more like tags along for the ride. Thus far he's been more than helpful. His closest associate would be the Thousand Sons marine Xerxzes - who's helping him experience the wonders of the galaxy. He's also involved in some form of techno-sorcerous experiment with Nissimon and Venera - something to do with the head of the Dusk Hag.

Illusion of normalcy: Appears as a normal human. Darkly handsome, but fairly nondescript. He prefers clothes and accessories that do not betray his status or nature. As a thrice-bound daemonhost his powers her severely curtailed - he certainly more lethal than a normal human, but he doesn't have any of the more exotic powers some daemons possess (pun intended).