The introduction of Generative AI tools such as ChatGPT or CoPilot has rapidly transformed organizational work practices. While strategic potential is widely discussed, the human implications of Generative AI adoption remain underexplored. This study examines how employees perceive and respond to the organizational implementation of Generative AI, and how these experiences shape their psychological empowerment and perceived performance. An integrated framework combining Unified Theory of Acceptance and Use of Technology (UTAUT), user adaptation theory, and psychological empowerment was developed and empirically tested. A sequential explanatory mixed-methods design was employed, combining survey data from 363 employees with 14 follow-up interviews. Structural equation modeling (SmartPLS) tested hypothesized relationships, and qualitative analysis explored underlying experiences. The study contributes an integrated perspective on the human side of Generative AI implementation, extending technology acceptance models with affective and empowerment mechanisms and that psychological empowerment functions as the primary mechanism linking Generative AI use to performance outcomes. This study demonstrated that the relationship between adaptation, psychological empowerment, and perceived performance is significantly positive. In other words, when employees actively engage with Generative AI, they tend to feel more empowered in their work, experiencing greater autonomy, competence, and impact, which in turn enhances their perceived performance. This finding highlights that adaptation is not merely a form of compliance but a psychologically beneficial process through which employees come to view Generative AI as a meaningful and value-adding tool. Practically, organizations should prioritize creating conditions for employee empowerment, through experimentation opportunities, role-specific support, and transparent governance, rather than focusing solely on technology deployment and mandating universal use.