Reread it again.
Very nice adaptation of extra chapters about Eris.
Altough... not yet all of them.
Let's just say that at current level of main manga, she is already training with Water God style user (and they hate each other).
I totally can see whole Eris sub-story made into full movie, or at least 40m OVA. But full movie about her? Damn.. that, would be so great...