This was really well put together and really well mixed! I always have trouble mixing the drums but you made them sound really good here along with everything else.
I don't know if this sounds like a boss battle song, it kind of sounds like an open-world area with horror parts into it. And there's one part where I kind of got a Zelda vibe which is cool ^^
Really well put together though! I also have Spitfire on my computer but didn't realize I can get that heavy of an orchestra sound from it, it sounds great!