She realized people who possess a Devils fragment can extinguish her sword energy. Which means that Arhad has had that ability the entire time as well.
So, even if she polish her ability to use sword energy, Arhad could with his power, just extinguish it. And he can also use mana and devine power, so he would always be at an advantage.
i know. i understood everything thats been going on but like... idk.. i think its just that her initial goal was to serve under arhad but she’s already fighting beside him right now so she seems aimless to me. and it feels like her being down just because she now knows arhad will always has the advantage, just doesnt seems like her. maybe its because it wasnt potrayed that well that it ruins her characterisation. like it feels like the author did that just because he needed a reason for her to cry for a romantic scene.
well all in all it just feels like the plot isnt moving at all ╮(￣▽￣)╭
They've established through the entire series that her goal is to be the strongest swordsman and win over Arhad.
In the previous timeline she became his enemy in that pursuit, but then swore to be on his side in this one.
My interpretationis this:
She still wants to be stronger than him, so she'll feel like she has a purpose, is able to protect and be useful to him. If she isn't stronger than him, then she would feel useless and like he doesn't need her; he'd be able to reach his goal without her.
the plot is just kinda weird now.. like i understand whats going on but like what the fuck is going on? like what the heck with that sappy goal? wheres the strong and cool ianna from the beginning? its like something happened but nothing actually happened..???