Correct. I absolutely loved this music - hence why I used it for her battle, it seemed fairly fitting. Definitely search up the song itself rather than using what's in the files - the battle theme isn't the full track that you find online.
A small note:
Something I find very amusing is how most players follow a very particular route, and plan it beforehand (involving the key) in pursuit of a "perfect" ending. I think it should be known now: Immediately, some endings may seem better than others, but in the long run, each outcome of Episode 4 will be beneficial in its own right. I implore players to follow their own choices rather than using the forums to achieve a so called "perfect" ending - as Desolation reaches its conclusion, you will find that no such thing exists.