PLOTHOLE: -aside from the fact that you have a way to measure magic power and that HP married Granger-
Over 100 Potters in Hogwarts currently?!
Magically powerful Granger?!
Eh, it was slightly awkward, with super!protagonist off the bat already. And no, super!nemesis just doesn't cut it -.-
We all want the main char to go evil! Dark Lord Potter
Before I even start the story I state that it is a sequel to Innocence Faded.
as for the power scale, I envisioned it with average being in the mid seventies, and 80 being slightly above average for a fully mature witch or wizard.
As for the superpowered protagonist, He's not particularly smart, and his nemesis (perhaps nemeses, I haven't decided on that yet) will be much more intelligent and cunning, an almost as powerful.
Though I think you were just being nice when you called it just 'slightly awkward.'
If you are a fan of Ginny, you may want to turn back now, as at best she won't even be involved.