Oz Vessalius (オズ＝ベザリウス Ozu Bezariusu)
The main character of the story, Oz is a 15-year-old boy
with blond hair and green eyes and is from the Vessalius family, whose father,
Zai, is the current Lord. His mother, Rechelle Cecile, was killed by the
Nightray family, but despite this, he keeps a bright, optimistic, and energetic
personality. The story of Pandora Hearts starts when Oz turns fifteen. During
his "Coming of Age" ceremony to celebrate this reaching of adulthood,
he was dragged into the Abyss for the 'sin of his existence'. There he meets a
young girl named Alice who turns out to be a Chain. Oz forms a contract with
her in order to escape the Abyss. Upon returning to the real world, he discover
that 10 years have passed. In order to find out the meaning of his sin, he
began to work as an accomplice of Break
as part of Pandora. During this, it is shown that when he was young, he worked
hard to gain praise and recognition from his father. However, he discovered
that his father hated him to the point of not wanting to touch him at all.
After experiencing this, Oz began to think that there were no guaranteed things
in the world. He thought of himself as weak and, in order to protect the people
around him, he should at least remain an obedient child and let harm come his
way rather than others.
After traveling into the Cheshire Cat's lair, Oz meets Jack
Vessalius and in turn becomes his 'medium'. Jack eventually speaks at Pandora's
headquarters and the public hail Oz as a 'hero'. Oz finds that he can swap
control of his body with Jack if he calls hard enough and may sometimes even
see snippets of Jack's memories. According to himself, he is quite skilled in
swordplay, particularly in domain of self defense. However, he has very little
real experience in fighting.
Oz likes cute, younger girls and flirts with them
frequently. He once wished to marry Sharon when they first met. Oz, himself,
thinks of Alice as his precious someone, calling her his "sun". He
believes that Alice is the reason that he is still able to smile.
Jack tells Oz that he has the "right" over Alice's
powers and that a seal won't be strong enough to restrain Alice's powers any
longer, giving Oz the ability to use B-Rabbit's power, even without Alice's
permission or Gil's help. Oz proves this when he is able to stop Alice's
B-Rabbit's power temporarily on his own; another time when Oz was almost
kidnapped by the Baskervilles at Latowidge, and then recently when he was able
to summon B-Rabbit's scythe to fluently fight his assailants inside Sablier's
illusion, despite the fact he had never used a scythe before. According to
Lotti, Oz was supposed to be the vessel for the sake of hiding the existence of
Jack Vessalius and should the vessel be broken, Jack’s existence will be
brought to light and the further warping of abyss’s will, who seeks for him,
will most probably interfere with the real world. Later, Oz reunites with
Gilbert and immediately meets with the person behind Oz's homicidal nature: Zai
Vessalius , his father.
It has been seen in chapter 45 that Oz has had a will to
destroy everything until Alice stops him. In chapter 46, however, according to
Break, Oz may not be the real Oz Vessalius, as during his birth, Oz's father
suddenly took him away and it is suspected that he may have done something to
him or swapped him for another baby. In chapter 70, it is revealed that his
body was Jack's all along, while Oz is actually the real B-rabbit. Being the
B-rabbit, created by the will of the abyss at Jack's demand, he has the power
to break the chains who keeps the world from falling in the abyss.
Oz's uncle. He is easy-going and very caring, especially of the members of his family. 
