Se7en
I hope MC won’t be a part of the “golden trio”, it’s so overused already… Harry and Ron aren’t very impressive in the original storyline… it would be better if he had his own “adventures” and didn’t care about the “main cast”. Well this kind of story would be harder to write, so it is very rare for fanfic authors to do something like that… and they only repeat the canon with little changes because of the presence of the OC. I remember only one story (+sequel) about an OC character who didn’t take part in canon storyline and had his own in the background (full of darkness) of unchanged plot. Probably most original idea for the HP fanfic i have read, only that unfortunately while idea was brilliant, execution was only so so…