Complex sentence: Aerith makes an appearance in the "Kingdom Hearts" series as a member of a group dedicated to defeating the Heartless; the group also includes other "Final Fantasy VII" characters and Leon of "Final Fantasy VIII".
Split into simpler sentences: Aerith makes an appearance in the "Kingdom Hearts" series. She is a member of a group dedicated to defeating the Heartless; the group also includes other "Final Fantasy VII" characters and Leon of "Final Fantasy VIII".