>the OST starts playing during the final battle
>music plays during the final battle
>OP Starts playing during final battle
>Final Chapter title is game subtitle
>Main characters from predecessor series shows up to help
A song you only hear once will never be played again and doesn't appear on the soundtrack.
>An anti-hero comes to the aid of the protagonist
>The OP and/or ED subtly change throughout the series, especially as characters are added or kiled.
>there is an eyecatch to separate part A from part B.