Soul or Soul Power (As some people call it) can be used for almost anything.
The limit to to Soul Power can do is limitless, but that depends on the user.
Soul power can be used in many ways.
It can be used to create attacks, enhance strength, healing, ect.
You can create all sorts of uses for Soul/Soul Power.
Everyone is born with it, but unleashing it is a really hard task for most people than are not ranked.
Every living thing has a soul.