Messer is an enigma to most members of Delta Flight and Walküre. His serious demeanor constrasts with the more carefree members of his squad. His amazing piloting skill is a testament to his discipline and zeal. He never hesitates killing an ally if they were infected with Vár Syndrome. He is a true perfectionist, and chastises those that fail to perform above his standards. Messer owes his life to Arad Mölders, who saved him while on a mission in Alfheim. Messer also shares a deep personal connection with Kaname Buccaneer, and unbeknownst to her, keeps a special music playing bracelet that contains her last song as lead vocalist of Walküre, AXIA. In his downtime, Messer enjoys spending time with Chuck Mustang's younger siblings, but doesn't realize that Chuck's older sister, Marianne Mustang has a crush on him. Messer was originally from the city of Marienburg, on the planet Alfheim. The planet was soon ravaged by war, caused by an outbreak of Vár Syndrome. Messer, a soldier at the time, was infected by the Var infection, and murdered his allies in cold blood. Arad Mölders rescued him and rehabilitated the troubled young man. Messer was able to suppress the infection thanks to a special bracelet that played Kaname Buccaneer's song, AXIA~Daisuki de Daikirai~.