Bounts
In the series Bleach, there are a group of humans with special abilities, called the Bounts. They live by consuming human souls, which can give them everlasting youth. Bounts normally consumer the souls of dead humans, but in rare cases have been known to consume living souls. The act of consuming living souls can enable the Bounts to age to a certain degree. They were created when an experiment by the Soul Society went wrong. An experiment where a laboratory exploded and sent particles from research cells into the human world, infecting certain humans, who gained eternal life.
Bounts originated at various locations in the world, but speak German. The names of their dolls are also distinctively German in nature. Some Bounts have bonded together, but traditionally they lived alone and had little to no interaction with each other. They lived by a code that strictly forbid them from consuming living souls. The Bounts need the help of the Quincy in order to have their bodies converted into spiritual particles so that they can travel to the Soul Society. Their objective is to gain vengeance on those who initially gave life to them. Learning of the Bounts existence, the Shinigami decided to erase their mistake by secretly purging all remaining ones.
Bount Dolls
After reaching a certain power quota, Bounts are able to summon a Doll, which is a subordinate to him and can grow to have substantial attacking power. The Dolls have to be released in order to use them, and must be subjugated by their masters. If a Bount is not powerful enough to contain a Doll, it is possible that the Doll can kill it. If the Doll or Bount substain critical amounts of damage during battle, the Bount can lose control of the Doll, causing it to go crazy, with the possibility of killing its own master. In order to summon a Doll, a Bount needs to undergo a ritual where they chant an incantation. The ritual needs to include the ingredients of the human body, including carbon, fat, magnesium, water, lime, phosphorus and sulphur. When the Doll is summoned, it is small in size and weak in power, but can gain features and abilities as the Bounts power grows.
The Bit or Bitto are mosquito-like beings that consume living souls and bring them back in the form of an elixir to the Bounts. They were also summoned by a ritual. When the Bount consumes this liquid, it can significantly increase its strength.
Bounts
After reaching a certain power quota, Bounts are able to summon a Doll, which is a subordinate to him and can grow to have substantial attacking power. The Dolls have to be released in order to use them, and must be subjugated by their masters. If a Bount is not powerful enough to contain a Doll, it is possible that the Doll can kill it. If the Doll or Bount substain critical amounts of damage during battle, the Bount can lose control of the Doll, causing it to go crazy, with the possibility of killing its own master. In order to summon a Doll, a Bount needs to undergo a ritual where they chant an incantation. The ritual needs to include the ingredients of the human body, including carbon, fat, magnesium, water, lime, phosphorus and sulphur. When the Doll is summoned, it is small in size and weak in power, but can gain features and abilities as the Bounts power grows.
The Bit or Bitto are mosquito-like beings that consume living souls and bring them back in the form of an elixir to the Bounts. They were also summoned by a ritual. When the Bount consumes this liquid, it can significantly increase its strength. 
