Source: Shadows of Gallowspire, pg(s). 62
In life, Gildais was a cowardly Ustalavic count with no spine for war or politics. Nevertheless, in 3203 AR, when the Tyrant returned, he managed to stand his ground against the hordes of undead. His stuttered demands and proclamations bemused Tar-Baphon, who threw him through the Wizard-King's Pit into the Negative Energy Plane. Tar-Baphon, not expecting Gildais to return as a winterwight, was pleased and browbeat him into servitude as his seneschal.
When Tar-Baphon was defeated and imprisoned within his own fortress of Gallowspire, Gildais was also inside. To avoid the wrath of his lord, Gildais hid within Gallowspire for many years, unmoving and silent. Yearning for the warmth of blood, and feeling regret over the dark deeds he did in Tar-Baphon's name, Gildais began to prostrate himself before the light of the Great Seal. One day, in 4711 AR, he found the seal losing its sting and simply walked out of Gallowspire. Gildais' escape dawned a realisation upon the Tyrant: only positive energy, not necromancy, could facilitate his escape.
After his escape, Gildais began a quest of redemption, but was still controlled by the empathic urging of his former master. He has been tracked by both the Whispering Way and its enemies, the rumour of a flaw in the Tyrant's prison being too dire to ignore.
In 4717 AR, Tar-Baphon telepathically commanded Gildais to commission the Six Wise Crows thieves to steal the shards of the Shattered Shield of Arnisant and replace them with fakes, then give them to Whispering Way agents. Gildais realised that his hopes for penitence were badly misplaced, and he only committed greater crimes under the Tyrant's control.