Complex sentence: Tougher notes that Julian reveals her influence on the decisions of Constantius, but constantly reminds his audience that the authority to decide on any given matter rests with the Emperor, not with the Empress.
Split into simpler sentences: Tougher notes that Julian reveals her influence on the decisions of Constantius. But constantly reminds his audience that the authority to decide on any given matter rests with the Emperor, not with the Empress.