Frontotemporal dementia (FTD) is the second most common cause of young-onset dementia and is typically caused by frontal and/or temporal lobe degeneration [1]. This degeneration impacts personality, judgment, and the ability to recognize emotion. Early diagnosis of FTD is critical for effective treatment, but current diagnostic tools often lack the realism necessary to assess social cognitive abilities like emotion recognition and theory of mind. We propose the customization of an immersive virtual reality (VR) experience to improve early FTD diagnosis by creating realistic social interactions in immersive environments. Our approach is two-fold: (i) an authoring tool that gives neuropsychologists generative AI support for writing a suitable dialog involving faux pas, picking characters and voicing them; (ii) a VR game in which patients observe the enactment of those scripted social scenarios, guided by a virtual companion. We discuss the main features of our current prototype, and identify some development and evaluation challenges ahead.