You nailed it! RIP Mary-Sues of the fanfiction world.

Your story is written better now, after adding a bit more. I think I understood it better though, mostly because of your explanation. I am glad you added a reason for the murderer's actions. That gave a bit of characterization to her, for otherwise she is a faceless killer with only a name and no reason for the killing. And because you had me read the parody on the Mary Sue story, it made more sense.

Your English flows better than it had in the past, but you did not make all the grammar changes I suggested to you.

Altogether I liked it, although Mary Sue is not my favourite subject!