I'm a fan of Mikoto, I like all his adventures and many traits of his personality.
Despite this, I can't help but say that until the end she remained an irritating and immature brat, even though she is apparently the main heroine of the series does not particularly develop her character, continuing to see the world in black and white, good and bad. She often judges the actions of others believing herself to be better than them when she is just a hypocritical girl who does not completely understand the situations of others, criticizing people like Accelerator and Misaki when in their behavior they have always meant others and to remedy the own mistakes, helping her a lot too. You can probably say that certain things he never knew about them and you can forgive them, but it pisses me off that until the last volume of the story he continued to express his contempt for the other two levels 5.
Another characteristic of his immature side consists in always relying on his powers, believing that it is enough to make some spark and everything is resolved, even if he has faced dangerous situations that he could not manage he learns a little too late that his level title 5 is not worth so much anymore, except in the last volumes of history. Let's face it that even though she knows the magic, she has not yet understood the strength of some of her users, ranked third in level 5, but if a global ranking of all the characters of the series were made ... she is in low rank.