>>535939083
Well in Kai's case she took over an entire school and was causing a bit of a calamity. All considered we were still pretty neutral with her and the game implies she probably could have kept going. Not to mention it looks like she does generally try to hide her identity sometimes.
Wakamo and Akemi are just pure ballistics. You would need significant or coordinated firepower to take them down. lol fox squad in jail.
Akira just seems slippery. She seems to be able to fool anybody not named sensei.

So short answer is nobody can stop them except for maybe us but we love all our precious students. Even Akemi.