It is the first form which moves backwards while fighting.
What else does 2 kata hold in the way of principles?
I can think of line reinforcement. The act of moving up and back on the same line either in the same direction or opposite. 2 kata has both.
What else?
That's interesting and I can't wait to get home to see what you mean.
But I have to wonder, do ideas like this make for a better probability of success if attacked?