@snakecomic He didn't. He said he can't hypnotize Saya anymore because of the limit with the weak flash of it. The Cellphone is still great, because it is a portable hypnotize device that works a couple of time, which is enough to get them to a location where the more bulky perm hypno blink is located.There is also some kind of dynamic that built itself up in the first 2 acts. Basically he uses the device a couple of times until his victims recognize what is going on, then he uses some way to finish them off and make them despair. Would be no fun if that wouldn't happen again.
All in all I found this chapter to be pretty weak, especially considering the last ones which were just amazing, but I guess the artist is building up to something bigger and it is just the first chapter of the new arc so hopefully we can see a bit more with the next chapter. I like the art but I would have prefered to know more about what he is actually up to as an advisor in the school. Also not fond of the new character yet and i would have loved to see more about what happened to Kaede and Saya in the meantime, but I am sure those two will show up again eventually.