K.K. Null is a name that conjures up a wicked and cruel nihilistic super-villain that could kick Ultraman's butt before breakfast and polish off the X-Men before afternoon tea. It's the perfect name for a dark lord of the underground, which is exactly what he is.
He spends most of his time in the bowels of the earth, and his special power is the ability to melt brains with a deafening roar that he claims is music. You'd probably label it "noise." It makes Atari Teenage Riot's drill 'n' bass sound like farts in the bath after a bowl of baked beans.
Null looks the part, too: a skinhead wearing a gorilla's torso and sporting the small goatee Lucifer made famous thousands of years ago. Basically, you wouldn't want to bump into him in an alley after dark in, say, that seedy cesspit of central Tokyo they call Kabukicho.