I was wondering about Rex.

When you get the brain you want for him, does Dr Henry transplant the entire brain into Rex? Because you would think the brain is your personality in that situation.
Or does he put parts of it in only?

If he transplanted the entire brain, it would mean Rexs personality was not in his brain, it was in the cybernetics.
And the brain was a processer not his self and personality.

He gains a diferent trait for each brain. I only give him Violetta and Reys brains. So it comtrols and changes something.

The thing is, if Rex's brain was his personality core, then it would'nt be Rex any more. Rex would be dead when Dr Henry takes his dying brain out. It would be Violletta or Rey. But I don't think that's the case.

I know the Courier gets their brain removed in Old World Blues. And talks to it. So apparently people live on as themselves without their brains.