I would say the piro wall of death would be close to a rolling harrier. That is if you are talking about rolling in a circle with the harrier. The piro wall of death is better defined as a pirouetting funnel or hurricane. Take the heli almost knife edge in a circle and start pirouetting. I will try to find a vid to show this. Right now I am trying to easy into a new maneuver for me which is a piro figure of 8 funnel that throws back and forth like pieces of the 'snake' manuever. Geez I do about as good of a job describing it as I do flying it
-Ryan