Jabbar held an acrimonious and ultimately deadly rivalry with the Dark Lord Haroun, commander of the Black Helms. Even when directed by Cyric to fight alongside one another on the same battlefield, neither leader would look upon the other except to engage in bickering and argument.
Both Jabbar and Haroun felt so much hatred towards the other that even mundane arguments led to nearly fatal acts. When arguing over admission standards for the Company of the Ebon Spur, each commander devised overly-intricate means in order to kill the other.
Jabbar bore with him what was the ultimate design for his personal battle standard: a golden scepter crowned the the skull depicted in Cyric's holy symbol. The Dark Lord Haroun wielded a similar scepter, though one topped with an iron-colored starburst, completing the symbol of the Mad God.
In the Year of the Unstrung Harp, 1371 DR, Jabbar led the Purple Lancers to rendezvous with the Black Helms atop a hill near the Way of the Lion, just beyond the gates of Candlekeep on the Sword Coast. The entire Company of the Black Spur was tasked with besieging the library-fortress and claiming the Cyrinishad for Cyric's church.
Believing that the arrival of the Loviataran Monks of the White Rod was an ill omen, Jabbar stated that the siege should be postponed until the intent of the Maiden of Pain's followers could be ascertained. A heated argument quickly erupted between His Deadliness Jabbar and the Dark Lord Haroun. When the Finder of the Book Malik el Sami dared disagree with Jabbar, the commander quickly tried to slay the filthy merchant with a poisoned needle. Jabbar missed his mark however, and inadvertently struck Haroun. The Dark Lord responded with a single swing of his starburst scepter into the bottom of Jabbar's skull, instantly killing the commander of the Purple Lancers. Both leaders of the company fell over dead atop their mounts.
- Troy Denning (February 1998). Crucible: The Trial of Cyric the Mad. (Wizards of the Coast), pp. 9–11. ISBN 0-7869-0724-X.
- Julia Martin, Eric L. Boyd (March 1996). Faiths & Avatars. (TSR, Inc.), p. 53. ISBN 978-0786903849.
- Troy Denning (February 1998). Crucible: The Trial of Cyric the Mad. (Wizards of the Coast), pp. 12–22. ISBN 0-7869-0724-X.