Yes, I was taught by Sensei Walk in Illinois. Yes, it is quite vicious because it is not a martial sport like many karate or taekwondo schools. It was designed for fighting and not self-defense per se. I have used a couple of wrist and arm locks for settling people down but never used any ballistic techniques on someone with the intent to kill. Hopefully, I never will have to. I highly recommend you find another sensei in your area if you can as it is not an experience that is easily replaced with other styles of martial art.