This study presents an innovative Mixed Reality (MR) assistive device designed to enhance grip stability for individuals with degenerative and age-related hand conditions such as Rheumatoid Arthritis (RA) and Osteoarthritis (OA). By integrating MR overlays with an advanced servo motor locking mechanism, the device provides dynamic grip assistance that adapts to user needs in real-time. The MR system offers interactive visual cues and feedback, supporting users in performing daily tasks with improved hand function and reduced strain. Beyond assistance, the device serves as a rehabilitation tool, guiding users through personalized exercises that promote strength, dexterity, and hand stability. This paper details the design and engineering process, highlights the potential clinical applications, and underscores the device’s role in empowering users to maintain autonomy in daily activities despite the challenges posed by RA and OA. The results suggest promising implications for leveraging MR technology in assistive healthcare solutions, particularly in enhancing quality of life for individuals with compromised hand functionality.