WHAT IF SHES KIDNAPED AND PRESUMED DEAD
Matrix is taken And Kusaru finally realised that he loves her to
After matrix dies (if she does idk) Shoto would talk to zombie and be like, matrix Bi used to tell me stories of this boy she knew when she was younger
(Shoto may not knoe zombies real name)
He'd be like his name was "Kusaru" she loved him very dearly but one day she was ripped away from him. Blah blah blah
WHAT IF SHES KIDNAPED AND PRESUMED DEAD
[S]Endeavor kidnapped her?
[S]when he finds her she's dying- and dies in his arms after cupping his cheek and saying "I never stopped loving you."
The absolute devastation
Of the annoyance who loved him who would always stick around him no matter what he did
And his childhood friend that was the only one to form a bond with
Both dying at the same time
(And the realisation that she had been there the whole time, sticking around him no matter what. No Matter What He Did To Her)
Matrix stuck around Kusura
Because either
A) she made a promise that she's protect him and never leave him
Or
B) she knew he'd need someone
Or
C) she just hoped he'd recognise her
We can do a fusion of a and b, she made a promise, and she could see past the hard exterior he built and still saw the Kusaru she knew.
Pft- C literally is "Notice Me Senpai!"
Another reason she stuck with him was because she needed him to- (it doesn't really make sense but shhh)