anti-skill aren't useless in vol 20. They are used as frozen brain controllers of the jet fighters of academy city.
Most of the anti-skill are military trained but forced to enter as a teacher for the public view. Aleister use those military experts as puppets for his plan. Because they are well trained in military's way and strategy they can execute that plans in war. But the problems are the fighter machines of academy city are too much even for a well trained human being. That's why they are just frozen solid and confine inside those war machines.....
........................well they are ...........useless
