"Natural Killer Cyborg" is a battle theme in Mother 3. It's only heard in Chapter 8, inside the Empire Porky Building. This theme is exclusive to the Natural Killer Cyborg, because of its atrocious nature and weaponry. This theme is mainly heavy metal, where the occasional electric drum set and electric guitar are heard.
The rhythm for this song is different in some parts. The first and third parts are rather calm, with a low BPM count. The second and fourth parts are a lot faster.