This is the name given to the poison that comes from Kiyoi's own blood when it exits from his body. The blood once infused with the oxygen of the air under goes a change thanks to a enzyme that turns the blood in to poison. The blood releases a stream of smoke till it completely evaporates. The Akuchi also acts like a acid which burns whatever it lands on which in turn releases more of the poisonous gas in to the air by releasing steam. The affects the Akuchi has on its victim is that it effects their nervous system cutting off all signals being sent out from the brain causing a case of paralysis. This is however temporary as it is not a strong poison but it would give Kiyoi enough time to land a decisive strike if it was not countered right away.