Uttam Luna Hesh Udar was a Custodian of the Legio Custodes during the Great Crusade and early Horus Heresy eras in the 30th and early 31st Millennia. Fighting on the frontlines of the Great Crusade, Uttam was sorely wounded while deployed against the Orks. He soon found his physical reaction times were no longer optimal and he was forced to retire from the frontlines.
He was then charged with a solemn duty as lead gaoler of the high security prison of Khangba Marwu, better known as "The Vault." Uttam was later killed during the performance of his duties when a group of prisoners -- all Astartes of the Traitor Legions -- managed to initiate a desperate escape.
During the Horus Heresy, Udar was the lead gaoler of the subterranean high security prison built to detain those individuals deemed hostile to the Emperor and isolated from the world above. Built beneath the Himalazian peak known as Rakaposhi, only the most senior Custodians bothered to use its original name, Khangba Marwu, and for those condemned to its cells, who would never again see the light of day, it had an altogether more prosaic name. They knew it simply as "The Vault." Udar was removed from the fighting ranks of the Legio Custodes after being exposed to an Ork bacteriological pathogen, whose aftereffects greatly reduced his reflexive response times to a level below the minimum required for frontline service amongst the Custodians.
A proud man, Udar took his removal from active duty hard, but eventually adapted and took to his new role as a gaoler at The Vault with the same determination and attention to detail that had seen him come the closest to the full infiltration of the Imperial Palace in the Blood Games until his peer Amon Tauromachian bested him. During his tenure, Udar was charged with watching the last remnants of the Outcast Dead -- a small group of Astartes warriors drawn from the Traitor Legions who were the last of the Crusader Host, an honour guard of Space Marines comprised of representatives from each of the 18 Space Marine Legions that served on a rotational basis within the Imperial City outside the Imperial Palace on Terra. Udar was slain when the Outcast Dead engineered a successful escape attempt. Udar was killed as he confronted one of the berserker World Eaters Astartes in close combat. The berserker in question, Sergeant Tagore, ripped out a section of Udar's spine through his chest, just as he had promised the gaoler he would during his confinement.
- The Outcast Dead (Novel) by Graham McNeill