Abuna Basilios began to spend an increasing amount of time at the Debre Libanos monastery after his health began to fail in the early 1960s. He left more and more of his duties to Abuna Theophilos, and spent more time resting and praying at the monastery, rarely making an appearance at the Patriarchate in Addis Ababa or at the Imperial Court. He was too frail to participate in the Conference of the Oriental Orthodox Churches held in Addis Ababa in 1965, and deputized Abuna Theophilos to represent him in most of its sessions.