This study investigates the efficacy of Non-Player Characters (NPCs) in the metaverse as a tool for enhancing the design thinking mindset of university students. Utilizing a controlled experimental design, we compared the design thinking competencies of two student groups: those who interacted with NPCs in the metaverse and those who did not. Over design thinking mindset questionnaire and four assignments, we measured dimensions of design thinking, including Human centeredness, Empathy, Mindfulness and awareness of process, Holistic view; Problem reframing; Team Working; Multi-/inter-/cross-disciplinary collaborative teams, Open to different perspectives/diversity, using a t-test for statistical significance. The findings reveal that NPCs significantly foster the development of Empathy, Problem reframing, and Open to different perspectives/diversity skills, which are essential to design thinking. In contrast, no significant effect was observed in the areas of human-centeredness, process awareness, team working, and collaboration in diverse disciplines. The use of NPCs was particularly impactful in complex tasks, as evidenced by the increasing effectiveness observed in later assignments. The results underscore the selective benefits of NPCs in metaverse learning environments, suggesting that their integration should be strategically targeted to enhance specific design thinking skills. The study suggests a potential for NPCs to play a significant role in long-term learning strategies, where a step-by-step skill acquisition could culminate in advanced design thinking tasks. These insights pave the way for educators to develop nuanced curricula that leverage the strengths of NPCs and for further research to optimize their use in educational metaverse platforms.