Mordax et al

My Trial of Magneto theory as of right now is:

I think Wanda did it.
No, genuinely. I think Wanda killed Wanda.
Either literally herself, or another universe version, or some kind of magical projection of herself.

I think there were somehow two Wandas that night, which accounts for that scene of Magneto and Wanda meeting up AFTER she was already dead by the timestamps.