Calistus holds two doctoral degrees: a PhD in Political Science from the University of Yaounde 2 Soa (Cameroon), where his research centered on diaspora studies, and a PhD in Development from the Africa Research University in Lusaka, Zambia, with a focus on International Development and Diplomacy. He has further strengthened his academic credentials through several certificate programs in conflict management, peacebuilding, and human rights.

Beyond his scholarly achievements, Calistus is the founding Director of the Cepress Policy and Development Institute at Cepress International University in Liberia. He also serves as APR Regional Editor for Central Africa and as a Research Reviewer at the African Center for Digital Transformation in Accra, Ghana. In addition, he contributes to the next generation of scholars as an external supervisor and examiner in the Department of Public, Constitutional and International Law at the College of Law, University of South Africa (UNISA).