If it's supposed to be a climactic fight, I'd nick
I love it because it's so unapologetically gothic and badass, just like sparda himself. No real intro or outro, or even some less intense parts. Just one blaring cacophony of organ rock. Perfect for a boss that is not just some demon, but the demon.
If it's supposed to be one of those sad fights you don't really want to have to do, I'd go with one of those slow sad piano/violin songs. Like this one:
If it's supposed to be one of those sad fights you don't really want to have to do, I'd go with one of those slow sad piano/violin songs. Like this one: