The Soul-Fire of the Underworld had nine states.
The Underworld Emperor had already mentioned the top three states: The first was "Seeking Fire"; the second "Possessing Fire"; the third "Absorbing Fire". The next was the fourth state "Lighting Fire".
The fifth state was an important level, similar to the Undefeated State of the Green Mountain Sect; it was because the Soul-Fire could be used for fighting at this level.
It was after the fifth state that the word "fire" was placed in the front.
The fifth state: "Fire Leaving".
The sixth state: "Fire Tempering".
The seventh state: "Fire Traveling".
The eighth state: "Fire Concealing".
The ninth state: "Fire Summoning".
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"The Control of Soul-Fire is not within these nine states, nor is it above the nine states either. That is because it isn't the tenth state; it is a totally different Cultivation method."