Von Geiz was a male individual who served as a Chief Medic in the 61st Mobile Infantry. He was fourth down the line of command after Captain Micha Evon, Lieutenant Sairgon and Commander Paonu. He was in charge of everything to do with the medical part of the 61st and was the one to clear soldiers when they got better. He served the 61st throughout the Galactic Civil War in battles such as the Attack on Haidoral Prime, where they extracted the defecting Governor Everi Chalis and the Siege of Inyusu Tor where the company face obliteration in the face of overwhelming imperial forces. Following the death of Captain Evon, Von Geiz took a more senior leadership role within Twilight Company. He supported Chalis' proposition for a campaign against the shipyards of Kuat.
Von Geiz was a kind, smart, thoughtful, caring, and sympathetic person. First Sergeant Hazram Namir considered him one of the gentlest people he knew. He was trusted Captain Evon. As the Chief Medic, Von Geiz was skilled with various forms of medical treatment and was also connected to every soldier in the company. For Twilight's traditional funeral ceremonies, he would assist in finding speakers for the fallen soldiers.
Von Geiz appeared in the 2015 novel Battlefront: Twilight Company, written by Alexander Freed.