Pffft, from the first chapter of this elf arc i pretty much was expecting this to happen, but it still hurts.
Everything is pretty much bullshit. So what? She is a bitch SO FREAKING jealous of her sister that decides to mind control a whole country, but everything gets solved and she turns into a good girl when she knows about what her sister did in the past? So all her childish tantrum gets solved knowing that her sister did something for her in the past? REALLY?
And then the bullshit with the father is almost as bad. So you sealed her memories because you didnt want her to suffer from losing that guy, but that guy got revived 5 seconds later and your reason for not unsealing her memories is because you are... weak of heart? FUCKING REALLY? Thats not a reason, thats the only frigging excuse the author could come up to bring up LOL
I have mixed feeling about the first arc. I mean, it was pretty good at the beginning but then he ran away leaving all his classmates being mind controlled and about to be used in a war, when not only he knows who is doing it, but he knows how its done and not only knows how to solve it but he has the means to do so xD. It was all kinda underwhelming.
Then the second arc, the dungeon where he met the elf girl is pretty good. Nothing extraordinary but good enough to keep reading the series. But this third arc... OMG, its so fucking bad.
I expect next one to be better. If not, drop and read something else. There are too many series out there to be bothered with only one.