Complex sentence: The Agyllians, or flamebirds, are in constant communication with Maruman, resulting in schizophrenic tendencies, he is prone to falling into fits of madness, and his temperament shifts without warning from prophetic and wise to sullen and difficult.
Split into simpler sentences: The Agyllians, or flamebirds, are in constant communication with Maruman, resulting in schizophrenic tendencies. He is prone to fits of madness, and his temperament can shift, without warning, from wise to sullen and difficult.