Details of Auguste's background are unknown.
Auguste has a muscular physique covered in a number of scars. His ears are pointed, though no explanation for this is ever given.
Auguste is very dutiful, undertaking a number of tasks, including less reputable responsibilities such as forging documentation for Miyu Edelfelt and Chloe von Einzbern. He has taken a specific interest in appraising Shirou Emiya due to Luvia's attraction to him, checking his physique, asking about how Shirou feels about his mistress, and asking him if he is "prepared."
Auguste displays prowess in hand-to-hand combat against Bazett, and shows skill with various weapons like firearms, explosives, and knifes. He is ultimately unable to overcome Bazett's strength even with the support of Luvia.
Auguste's fight was only briefly depicted in the manga, but extended in the anime adaptation at the author's request.