To clarify the strength system in this world:

Every stage is divided into initial, mid, advanced and perfect.

Cultivation-stages:

Mortal Stage

Spirit Energy Stage

True Energy Stage

Transcendent True Energy Stage

Immortal Stage

There are 3 forms of energy.

First, vital energy.

Second, spirit energy.

Third, true energy.

Each energy gathers in a specific, definite and different core and has a different effect.

Vital energy is the energy which supplies the body directly. It is necessary for living and it also directly defines how strong your physical body gets.

Spirit energy supplies the spirit of a being. Forming a spirit core means also, that it will form intelligence. It also defines your capacity to use spiritual force, so force which exceeds pure physical strength.

True energy is the energy which sustains any other energy. It is literally the true and original energy, filling the entire world. Vital energy and spiritual energy are solely forms of it, the original form is the true energy form, which is also the purest and most potent form of energy.

Because of that, true energy cultivator bodies will naturally start to influence the other energy forms by refining them into a purer and therefore more potent form.

That's where the term 'transcendence' is coming from. It describes a certain degree, of how much true energy one possesses, and therefore how much of ones other energy forms are already refined into a truer energy-like state.

And if one reaches the point, where both lower energy forms in their respective cores are refined into a state of true energy, the immortal stage is achieved.