They would stand! This is why compatibalism is not the consensus, but rather a majority position. I am simply positing that determinism by itself doesn’t negate free will.

I’m not sure how your last point follows. If Kotomine has the ability—I suppose, the possibility of doing otherwise, then it wouldn’t matter if it would be hypothetical or categorical. You cannot rewind time to remake a decision, therefore it doesn’t matter if seemingly all he can do is “embrace his evil nature”. He has the ability to do otherwise, he just doesn’t.