Subject: Wait, I'm not sure if it counts though.
Author:
Posted on: 2015-07-22 13:59:00 UTC
The Sue did plagiarize the plot, but didn't pretend to be Madoka - she (an american tranfer student called Angie, apparently) just shoved her out of the way and had everything happen to herself instead.
And, well, it wasn't Madoka killing her but Homura, who's basically Madoka's protector in canon.