Tnzyl Brnamj Strym Snayb Bbjy ⇒

I approached tnzyl brnamj strym snayb bbjy with an open mind. Maybe it’s experimental poetry. Maybe it’s a lost early-2000s forum username. But after several attempts at decoding (ROT13? Atbash? Keyboard shift?), I’m left with nothing but a mild headache.