In Japanese folklore, the figure of the vengeful spirit is a powerful one, symbolizing the unresolved issues of the past that continue to haunt the present. Ayaka's story, while tragic, is a reminder of the human cost of rigid social norms and unrequited love.
In later arcs (specifically the Liberal Arts City arc in the manga and subsequent filler arcs in the anime), Ayaka returns not as a villain, but as a recurring ally. mutou ayaka