It is kinda interesting that the writing is showing us that our mc is not perfect. Attitude specifically. Ignoring his obsession that looks interestingly immature, naive and cute? he is unexpectedly not composed at all. Youd expect he would be do perfectly with the fml's tutoring but naw. And now also with the fighting.
I dont hate it but at the same time, i wonder if this actually clashes with his character. Unless hes very expressive/animated/flustered actually because the fml asked him to be more "human" but it is probably more likely because of his hidden sickness that causes him to be mad crazy or something.