They do make you invincible, but they fail if you mess up the prompts. Did any of them cause you grief in particular? I find the student one to be the most difficult one personally.
I may have failed an input and thought that I got hit. I will test this out.
Ok, after a lot of testing and now getting good at landing it, I can confirm that it was in fact a misinterpreted skill issue on my part. Derp!
