Yoru

Yoru (夜 Night) is a hollow created by Weiss Shirame. He is an experiment to domesticate hollows and is currently a success. He travels within a flask, normally carried by Sora Kurohane and devours Hollow's tainted souls in order to grow.

Physical Appearance
Yoru is a small ball of what appears to be darkness with teeth and a single red eye. He is kept inside a flask with two prongs that are plugged in order to keep him from touching the outside world.

Personality
Yoru is a high spirited indivdiual with a personality larger then life. He is adventurous, wanting to constatly travel all over the world and experience different things such as "western music" and "egyptian cuisine". Although he wishes to explore, he does not enjoy interacting with others, other then Sora, Weiss or Kuma. He can be quite rude and abrasive, often cursing and threatening to eat people he is not comfortable being around.

Yoru has a hard time staying quiet and loves to voice his opinion on any sistuation. He also has the bad habbit of singing out of no where. The only trait he seems to share with your average hollow is his unquenchable thirst for souls, often yelling that he has a need to feed.

Inside the Flask
While inside the Flask, Yoru has the ability to use normal Hollow abilities such as Cero and Bala. This is thanks to the specialized matierial of flask being made of Reiryoku, which amplifies the blast without it destroying Yoru's container.

Outside the Flask
Yoru is only able to remain outside his flask for about ten seconds at a time. In that timeframe he can expand his body to massive proportions in order to devour something. Normally being a hollow, Yoru can swallow something whole in order to eat it souls.

Background
While conducting experiments on the Human Soul, Weiss discovered he could split pieces of his soul. By using his blood as a physical medium, his soul manifested itself in the form of dark matter. In fact this dark matter was a hollow who's personality and appearance differentiated from the average hollow.

The innovative discovery of this Hollow led Kisuke to pursue the possibility of domesticated Hollows that could fight for the good of man. The hollow was named Yoru and took on a very human and friendly personality, it took a quick liking to the members of the Shirame Shop. Yoru possess the hollow ability to eat souls, but is restricted by Weiss' rules to only consume the souls of other hollows in order to make Yoru stronger.