Yeah of course it needs practical aspects too. Charles is, if anything, too powerful a telepath to even test anyone. There's no real 'mental fortitude' skills that can deal with him, he's just too much. They'll know who Scarlet Witch is and the fact she's pretty good at forcing people to experience illusions and false versions of reality. So that might be the biggest thing to focus on practically. She's definitely the most notorious telepath in the brotherhood.<br/><br/>Not everyone who does the theory would have to do the practical though since those are quite different things to be willing to do.