William tried to lower his speed, but that didn't make much difference already, so he aimed toward reducing the distance crossed in his next attempts.
The physics of the lightning element were unforgiving; the "ignition cost" of the dash was the primary drain. By shortening the path, he was essentially reducing the "burn time" of the technique.
The technique allowed him to flash for more than a hundred metres without any problem. But to make the spirit power consumption lower, he had to decrease the range from one hundred metres down to thirty metres only.
In return for such a decrease in range, the spirit power consumption became less than ten percent. And for him, this was simply perfect!
It meant he could theoretically perform the dash ten times on a single tank, or—more importantly—save that energy for the destructive follow-up.
