Sssair Gleamling is a Keeper of Secrets, a Greater Daemon of Slaanesh who led a warband of daemons known as the Murderval. He was tricked into giving up control of the Murderval to a Daemon Prince of Tzeentch named Corflich Loatheheart and was imprisoned within the Impossible Fortress of the Lord of Change within the Realm of Chaos.
The origin of the Greater Daemon Sssair Gleamling is not known amongst the savants of the Imperium who study the dark secrets of daemonology. But what little information that can be gleaned from various sources is that Sssair Gleamling was once the master of a powerful warband of Chaos daemons known as the Murderval. The Dark Prince had formed this formidable host comprised of daemons from all four Chaos Gods in order to attack the Aeldari world of Lohiac in order to obtain souls.
Slaanesh ensured the cooperation of the other Ruinous Powers by bargaining gifts and worlds to ensure their compliance. No less than four Aeldari Craftworlds banded together to defend the gateway on Lohiac that could gain the daemons entry into the Webway. The war between the Murderval and the Aeldari lasted for many solar years, until finally, the daemons closed in on their prize.
The gateway was protected by 3 powerful Avatars of Khaine. Using great cunning and guile, Beasts of Nurgle known as the Mouldkin attacked the Avatars en masse. Distracted by this threat, Sssair Gleamling launched the Murderval into a flanking attack and utterly annihilated the Avatars. With the prize in their grasp, the daemons were ready to enter the Webway, but their plans were foiled with the arrival of a new threat in the form of a Drukhari host lead by a troupe of Harlequins.
Bogged down by the Aeldari reinforcements, this allowed the Aeldari Seer Council to seal the Webway portal permanently, denying Slaanesh his prize. Sssair had failed his dark patron in achieving his covetous prize and had been defeated by the valiant efforts of the Aeldari of Lohiac. Leaving his host bloodied and humilated, Sssair's power and influence was left waning.
Soon a rival Daemon Prince sought to gain prominence in his stead. A beautiful and cunning Daemon Prince named Corflich Loatheheart sworn to the Lord of Change, Tzeentch, duped the Greater Daemon of Slaanesh into yielding the power of the Murderval into his stewardship. He promised Sssair Gleamling that he would return the daemonic host once it had claimed its millionth soul for his patron god Tzeentch. But Sssair had been tricked, and soon found himself imprisoned within the Impossible Fortress, Tzeentch's home within the Realm of Chaos, and the leadership of the Murderval fell under Corflich Loatheheart's control.
- White Dwarf 368 (UK), pg. 27
- Corflich Loatheheart at Games Workshop website