Credens Justitiam - Mami's theme from Puella Magi Madoka Magica. Not entirely sure what a good use for it would be, but it's awesome and epic so I'm sure someone experienced in using music for games can see something.

Septette for Dead Princess - Remix of the original by Ezel-Ash. Epic instrumental piece suitable for grand fights or as a leitmotif for someone powerful. Given the name it would be especially useful for female undead and it was originally the theme of a vampire.

Evening Dies on Dendara Field - Original composition by ZUN for the album Ghostly Field Club. Just kinda haunting and suitable for any sort of foreboding scene before anything actually happens.