A mystery that seems to shadow you at every step, ever since you narrowly escaped him at Harfeld Manor, identifying Audran is a big step towards resolving the doom that hangs over the Flux State. Audran is an ork with skin grafts, received when he was admitted to a Berlin hospital with third degree burns over 60% of his body, massive blunt force trauma, and irradiation to the tune of 5,000 millisieverts - a dose that is known to cause death. He had no identification, nor could he be identified. Amsel theorizes that was due to him being a member of the Disciples of the Cleansing Fire cult that worships Feuerschwinge within the isolated SOX wasteland.
Audran appears first in the Harfeld Manor, trying to kill your team for breaking in. He eventually retreats if dealt enough damage, but he returns to haunt throughout the investigation.
Audran is also the final boss of Dragonfall. His main threats are his minigun and heavy armor; destroy his armor and cover, and he'll be ripe for the picking.
If you didn't convince Adrian Vauclair to cancel the plan, then Audran dies without making a fuss, and your last confrontation will be with the doc.
If you did, then as Audran is dying, you have the chance to finish him off personally, with his own side-arm.