Complex sentence: She is the first magus to appear in front of Arata during the Black Sun gravitational phenomenon incident in Arata's world where she was sent to investigate it; this incident eventually led her to introducing him to the academy.
Split into simpler sentences: She is the first magus to appear in front of 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.