I think all three influence each other.

And maybe the mind is the part that body and soul are fighting over.

It seems like the mind is a hellscape of illusions and delusions of grandeur when it is under control of the body. It becomes the body's apologist, finding excuses for all it's selfish desires ("I'm special, I'm a victim" etc).

But when the soul takes over the mind it becomes a beautiful and useful tool able to deal with ethics, truth and problem solving.

But realistically, there seems to be mostly a state of change, where sometimes the body controls the mind and sometimes the soul, at least inside of those who put up a fight.

Those who don't put up a fight will have their mind completely controlled by the body (beast), and the soul in a coma.