Aka Manah

This is a technique that represents the 'darkness' of Angra Mainyu's heart, and the truth of his being; it is the third ability granted to those who awaken the abilities: Indar - which symbolizes the "gluttonous aspect of sin" and Kshathra Vairya - which denotes the "encumbering, influential nature of sin". It allows him to tear open a ripple no wider than the width of a hair within his vision. Through this tiny gap, a substance closely in the form of black mud will seep out. Descending upon the surface below, the 'thing' will rapidly flood the relative environment. Neither physical or ethereal surface can accommodate that inky black substance at all, both will rapidly erode, as if being consumed whole by this hellish entity. Even a slight touch of the substance can prove fatal, which will gluttonously devour anything imaginably possible (within reason).

After approximately an hour has passed, the mud would cease pouring out from the 'sun', and the bounded field would fade away. But by then the mud would have sparked a fire of enormous proportions; the people who had been unable to escape would turn one by one into burnt black corpses. A magnificent red lotus of fire would bloom in the [night(?)] sky; on the ground would be staged an endless banquet of death. Even those who might have survived through means of a life-resurrection/sustaining ability would, 'lest their will be more reinforced than diamond (in a metaphorical sense), will be enslaved by the horrific scene before them, of which proves nigh-unbreakable without external aid. The scene which will eventually be staged, is akin to 'hell'.

However, this technique does serve a much less destructive, more resourceful purpose, one which a nameless villager was subjected to in the process of becoming 'Jashin'; by opting to corrode only the organs of the victim and replace them with artificial counterparts, they may attain 'immortality' as a result, although they would be reduced into a comatose state for a varying period of time depending on the experimented's willpower and vitality, and even then, they may never wake up again. However, the one who made such a process even possible may choose to strip them of the rather generous gift at will, should they manage to survive, needing only making physical contact with them to trigger the destruction of the false organs, and revert them to what they were originally - the 'thing'.

All in all, Angra Mainyu is impervious to the deterioration and the combustion that will eventually engulf those at an elevation so high that virtually all ground-dwellers will be entirely 'baptized'.

Origin
The 'thing', the black mud which entails the chaotic capabilities it poses, was originally what in addition to Hashirama Senju's DNA granted Angra Mainyu his 'immortality', as well as fabricating what could otherwise be considered his 'eternal nightmare', induced on part of the Land of Demons. However, this substance proves to be exceedingly more potent, a hypothesis turned reality.