But then the author would have to do some crazy explaining about what would happen to the mage association, her grimoires and political power balance between the remaining central powers, all that while keeping a natural story pace. Like, if she dies or the author will take a huge amount of time to finish explaining this or he will leave a lot of things unexplained (i think)
I get that the idea of rock-paper-scissors is often emphasized on this. But I think Serie dying in this time especially to a human warrior can't be justified just that. I mean, Serie has lived over a thousand years and during that time she has been learning magic. If all that time, she didn't learn anything to create magic to counter physical attacks or something, then i don't know... otherwise they will really to have some explaining to do in the latter. And a lot at that should be.
I don't necessarily hate the idea of serie dying, there just has to be a good ass reason. like the series has reiterated tons of times, fights between mages is like rock paper scissors and if a mage is attacked by a skilled warrior its kinda over for them. It also doesn't mean the person who will kill serie won't be killed by someone else, like frieren and her party. Though serie seems extremely powerful to us and to a lot of characters in the story, it doesn't mean she's invincible. Sure, she lived a long life, but she's not immortal. As time goes on and humanity advances, powerful people of the past will gradually fade with the passage of time.
All I know is that by the end of this arc, it's gonna be peak CINEMA as usual.