ever watch the Matrix the garb Neo wore into the building with Trinity to rescue Morpheous would be my first choice, I guess I would have to choose the shadowy robes of a death cult off this list though.
BTW Nice reference to Vader. I guess another option would be to wear the mlack shirt with the wordEVIL on it like Ozzy. you know to avoid any cinfusion by those pesky "HOLY" types.
Modern Day? Sleek, stylish three piece black suit, with a dark red undershirt and white tie. I'd keep my hair all punk rock and spiky, like it is now, and keep the goatee. I'd wear Oxford cut black leather shoes, with flames detailed on them in red/orange leather (I actually own these. ).
Odds are, I'd have a gun in there somewhere too. Or a ferocious knife.
Fantasy? A belt composed of iron chain links, with a loincloth. Only, this loincloth is composed of various heads hanging from that iron chain belt by their very long hair. Flame tattoos (in color) would rise up from my waist, stopping around my chest, as well as similar tattoos rising from my arms at the wrist. Two burning wings would sprout from my back, and I'd have my blonde hair hanging long and ragged around my face.