He was one of the victims of the reign of terror unleashed by the usurper Andronikos I Komnenos (reigned 1183–1185) in 1183, who had him blinded, though possibly not completely, then thrown into prison, because he attacked a court eunuch who blamed the disasters befalling the empire on the incompetence of Andronikos' predecessor, his under-age nephew Alexios II Komnenos (). Donald Nicol argues this shows he was a partisan of the House of Angelos, and he had his reward when Isaac II Angelos () came to the throne in 1185: the new emperor give him the rank of "Caesar" and appointed him to command the expedition against the Bulgarians in 1186, who had recently rebelled against the Byzantine rule and had restored the Bulgarian Empire. The rebels did not oppose the Byzantines in the open field, and instead retired to their mountain stronghold. John followed them there, but due to his overconfidence neglected to fortify his camp and allowed it to be surrounded, suffering a humiliating defeat. His robes of office were captured and displayed by the Bulgarian leaders Peter and Asen. John was relieved of command by the Emperor in favour of Alexios Branas, and lived in retirement.