I am thinking I will have some parts where she is reasonable and normal during certain situations though, when it is more appropriate (like I had somewhere in my CS, not completely detached from the real world)

Hm... I think I will make her an elemental warrior, imbuing her fists and kicks with the elements!
Or maybe just chuck a whole bunch of things in at random. Of course adding more to her imaginary background is what makes a chuunibyou fun!

There's two seasons and a movie you know of chuunibyou? (Movie is mostly a recap of first season though, but leads in a bit into the second season)