The chromatic harmonization instantly sets the spooky Halloween vibe. There are many other techniques you used that I think add points to the jam theme category: the kick beats feel like a heartbeat which is a nice touch, the pounding low piano feels like a ghostly drone but also adds energy to a fight situation, the upward piano/brass arpeggios feel like a rising ghost, and many others. The subdued outro was an interesting touch and maybe hints at the aftermath of a gruesome duel or the succumbing to Death’s call. Good work and thank you for sharing!