"Otogakure" is not in the list of possible values (Allied Shinobi Forces, Akatsuki, Root) for this property.Otogakure
Little is known about Achaeus's life before appearing one day in Otogakure, other than that he was once an inhabitant of a far off land. He is unaware of his own age, believing himself to be the age he appears to be.
Achaeus is only aware of his own memory through flashes of a traumatic torture, hazy images of his own limbs being removed and puddles of blood.
He is commonly referred to as "Ache."
Achaeus's current state of consciousness began with him awakening in an Otogakure river. He was taken in by an old woman who tried to feed the frail looking young man although the food he devoured only quenched one of the two hungers fighting for dominance within his body.
The second hunger inside him proved to be too relenting for Ache to ignore for long, so he spent weeks eating as much as he possibly could in order to quell it. When nothing proves to do the trick, Ache's hunger drove him to murder a criminal after witnessing the assault of a young girl. In a momentary loss of control, Ache ripped open the man's throat and fed on his blood. This action left him full of a new strength and without hunger.
Ache abandoned the old woman, fearing for her safety after his own grisly nature is revealed. He began to sleep on the streets and kill criminals as he came across them, keeping himself powerful and alive at the expense of their lives. He was eventually discovered by Becquerel, the current Otokage. Achaeus quickly developed a fascination and admiration for the powerful man, swearing him fealty and dedicating his own life to carrying out the Otokage's will.
Achaeus's default demeanor is typically cold, distant, emotionless. He observes human beings interact around him, studies how he should behave. He tries to go through the motions of a normal person, but this usually looks extremely mechanical or just bizarre to those he encounters. There are cracks of the Ache he once was that appear sometimes, a boyish laugh or a childish outburst.
The other side of Achaeus usually only rears its head in long stretches between violence in his life. If he hasn't fed on the blood of a human being for a while, he will slowly become more irritable and aggressive until he kills again, thus restarting the cycle and becoming cold and passive.
Ache has a mop of jet black hair that perpetually remains the same length, never growing or needing to be cut. His face is sharp and pretty, the pure image of youthful beauty. He isn't very tall and is pretty thin, leading many to disregard his aggressive tendencies until it is too late. He has two fangs, one in either corner of his mouth, that protrude over his lower lip when he smiles..
He typically wears black from shoulder to toe, including a shirt, pants, and boots. If in cold environments he will also wear a thick coat, although his vampiric nature mostly leaves him impervious to temperature.
Achaeus's body is essentially fueled by two sources of sustenance. He must eat food like a normal human in order to keep his stomach full, but he must also feed on the blood of human beings in order to keep up his supernatural strength. If he goes too long without blood, Ache grows frail and animalistic, eventually losing his mind entirely as his body acts on its own and forces him to feed on whatever is nearby.
Ache ultimately decides to choose his victims in order to prevent him from devouring someone he actually cares about.
Ache is capable of growing long claws in order to fight opponents, but his main method of battle is a thick black chakra shroud that envelopes his entire body. Ache manipulates this shroud into a variety of chakra weapons and uses it to create his own style of combat, inventing new shadow techniques with each fight he stumbles into.