In this paper, the second part of a two-part series, we explore the cultural stability of the Association of Southeast Asian Nations (ASEAN). The analytical framework adopted, formulated on a background of social cybernetics, uses Mindset Agency Theory (MAT) within a metacybernetic framework. Our exploration involves a thorough investigation of signs pointing to cultural instability, identification of potential pathologies, and the provision of insights into the underlying dynamics within ASEAN. Expanding on the theoretical foundation established in the first part, we explore the notion that regional organisations (ROs) like ASEAN can be viewed as complex adaptive systems with agency. Heterogeneity of RO membership can be both beneficial and detrimental, especially when this delivers cultural diversity. If detrimental, pathologies can arise that affect both ROs’ institutional dynamics and their affiliated regional organisations, a significant interest of this paper. In response to certain cybernetic aspects introduced in part 1 of the research, MAT is shown to be a specialised framework imbued with systemic and reflexive elements. Through this, the analysis sheds light on how an agency’s mindset connects with its behaviour and performance. ROs exhibit coherence in their operations when they successfully achieve adaptive goals. ROs, as agencies defined through a population of state agents, have mutual relationships and are encouraged to pursue shared regional objectives, such as economic growth, social welfare, security, and democracy. However, in highly diverse cultural environments, this poses unique challenges to achieving and maintaining cultural stability. The analysis scrutinises ASEAN’s behaviour, relating it to manifestations of cultural instability, and deduces conditions that encompass an inability to undertake collective action, covert narcissism, and a lack of authority. Employing MAT as a diagnostic tool to comprehend ASEAN’s intricate nature, the paper concludes with practical recommendations aimed at enhancing ASEAN’s cultural health and sustainability. The ultimate vision is to foster a more integrated and proactive regional entity.