Nikkyo is not evil. The way these guys are practicing it it looks ineffective...but not evil.
Nikkyo is a way to learn about pain and injury and submission and relaxing into effective technique.
The way Nikkyo is being practiced in this video most people could just take their hands out of the grip...a technique to neutralize it is not needed.
The use by me when practicing this technique, not one I think would present itself much in an actual situations, is as a means to decouple the uke from the ground, to float them, to rock them on to their heels.........when I do this one I am working the uke's feet....intention down the arm,shoulder...through the back and to uke's feet.........