Complex sentence: It is later revealed that Sheryl is apparently a failed experimental subject called "Fairy 9" and is "discarded" by Grace O'Connor on "Galia 4", the latter stating that she had outlived her usefulness.
Split into simpler sentences: It is later revealed that Sheryl is apparently a failed experimental subject called "Fairy 9". She was "discarded" by Grace O'Connor on "Galia 4", the latter stating that she had outlived her usefulness.