Fiona used her blessing multiple times during that conversation with Mark! Usually, there would be some sort of reaction from him whenever she uses her blessing to try and control him! Either he would notice that she used her blessing and ignore it or he would glare at her for using it on him and tell her never to use it again! But there was always a reaction from him!
But this time, there was absolutely nothing!
It felt as if Mark did not even notice that she used her blessing on him at all! Every time, she used the blessing while talking, she noticed that there was no reaction from Mark, he just continued talking like nothing happened! Fiona was certain that Mark's mental fortitude was so strong now that there was just no chance of her blessing reaching him!
Is this not the same thing that happens with the Undefined superhumans?