Nirvanic Flame Physique!

Without second-guessing, Donghai walked toward the black door. Pushing it, it creaked!

Creak-Creak-Creak! Upon hearing the creaking sound, the door budged easily, and he stepped into the pitch-black darkness behind it.

The moment he stepped inside, he felt a strange energy signature slightly similar to the one he had experienced not too long ago in the Limbo realm that lies in the interface between the heavenly, Tenth Plane, and Underworld Realms.

'So this must be the darkness law that chains every dead soul. I get it. My job is to comprehend them.' He wondered as his body kept sinking into the unknown dark abyss. 

The next thing, he changed his posture by crossing his legs in the lotus position. Shutting his eyes, and starting his meditation, he soon entered a state of Selflessness. 

Just like that, he began comprehending the path of death from within the law existing in that abyss.