'History written by the victors' ... *shudder* Such scaring truth.
*blinks* So we might be going though term 8??

Well, I can't tell what happened then either seeing 'Nadia' entered the school in the so-called 'third year' (according to Hogwarts, A History), the year of the Tapestry. And, an Inquisitor?

Now, now, how interesting... (maybe we should be able to tell by the date of the realease of OotP, seeing the Inquisitor idea must have come most surely with the introduction of the Umbridge character. If the terms have a predeterminated month-leght, we should be able to erase the extra-years.)
The last words Professor Elensar heard were "you failed me" coming from Voldimortist (in her head, so Nadia is not supposed to know

) so if she was supposed to kill Marcella she surely couldn't. Again, the flying spell would have visible (save it was performed from very close to the other body, save Nadia and Raven's plan of using a snowstorm.) Enough rambling, you can take your own guesses.
By the way, I think I have the username of the student who was expulsed after performing the Killing Curse (and supposedly killed GoldenLugia) but I have tried PMing him/her and s/he won't respond. I'll look for it if interested though (if not erased for inactivity...)