(Theory) Brain is the impostor.

[Harsche]

I don't know if this is the right place to post theories, pls correct me if it's not.

So is it just me or many things are implying that Brain is the impostor? In the latest story update in jp Union X there's this line:

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Brain: This world is moving along a fixed path - of ruin. Overwriting the memories of the Keyblade War didn't change that. I'm going to become the virus that rewrites the program that is this destiny. (Translated by fan)

And then there is the secret report in KH3 (11 or 12, I don't remember) in which...

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(Probably) Luxu says that there's an impostor that is like a "virus" in the system created by MoM.

So basically that means that Brain is going against the Master's plans and that means he's the impostor. What do you guys think?