I agree it's not metal, but it's definitely industrial. I'd call it power noise or electro-indstrial. Metal usually means guitars, not synths to me- however the sub-generes of industrial are confusing and mixed up. They're mostly whatever a band wants to call themselves, and most of them make music that fits into all of them.

From his own Bandcamp page: "Author & Punisher is an industrial doom and drone metal, one man band". Every review I could find describes the music as "industrial metal". Maybe your definition is off?