The energy all spirit masters cultivate in order to increase their spirit ranks and nourish and upgrade their martial soul. Soul power is easy to cultivate for the first forty ranks, but the growth speed would slow from there on. The speed depends on a few factors, the life stage of the planet the spirit master resides on, the cultivation method, talent of the spirit master, their age, and etc. A spirit master can use their soul power in a variety of ways. Examples include communicating with other people from a short distance, exerting pressure on an individual or a group of people, pushing a person or a group of people away or pull them towards you, and many other things. Since soul power is a type of energy, it can be used to power soul devices and soul weapons.