Complex sentence: She is the first magician to appeared before Arata during Black Sun gravitational phenomenon incident in Arata's world where she was send to investigate it, such incident eventually led her to introducing him to the academy.
Split into simpler sentences: She is the first magician to appear before Arata during the Black Sun gravitational phenomenon incident in Arata's world where she was sent to investigate it. Such incident eventually led her to introducing him to the academy.