Each one of the NPC's within Nazarick have sheets worth of data that describe there hobbies personality etc.Albedo was created by Lord Tabula Smaragdina and is the only one that has their character info fully written by the Author!

She is a demoness who holds the title of Guardian Overseer, which is the
highest-ranking position in the Great Underground Tomb of Nazarick. With
flowing raven hair and golden pupils, her beauty could bewitch a nation.
She is proud of her position and confronts intruders as a confident, dignified
superior being.
Regardless of how brilliant or brave her foes are, or whether she considers
them strong, she will never acknowledge them as being equal to herself.
This is because she understands the meaning of the position bestowed upon
her.
Her abilities befit the title of Guardian Overseer, with outstanding intelligence
and combat ability.
That said, she is not omnicompetent. For instance, in pure wits, Demiurge is
her superior, while Shalltear is superior in fighting ability. Yet, nobody in
Nazarick can rival her administrative ability.
In addition, her feminine skills -- particularly those pertaining to being a
housewife -- are excellent, and during her free time, she can be seen sweeping,
sewing, and so on.
Though the reason is unknown, she enjoys cleanliness and her desire for such
frequently drives her to clean things up.
In particular, her ability to sort out bookshelves knows no peer.
However, she recognizes the possessions of others as belonging to them, so
she rarely insists on cleaning up.

That said, the items accumulated through her collector’s habit are typically
very messy.
Therefore, it remains to be seen whether she actually likes being tidy.
This might well be an act -- in order to appear as the perfect woman -- though
the truth of that is unknown. It is too scary to confirm.
She always has a gentle smile on her, and her elegant way of speech has made
many people think she is a goddess or an angel.
That mistake is not particularly laughable, given that she is surrounded by
that sort of atmosphere and acts in an appropriate way.
The fact is, it would not be wrong to view her in that way.
She was originally planned to be an angel of the highest order, but she ended
up with a greatly distorted appearance after being fused with a monster from
the land of dreams.
Because of that, her personality is similarly twisted, being merciless and cruel,
cunning and savage. She gives her enemies despair and revels in their
agonizing deaths.
Her usual expression seems to be there to suppress the urges which flow from
her heart -- a mask which exists to conceals her desire to perform ruthless
acts upon the weak.
If the mask breaks, she would probably end up being like Empress Lu Zhi or
Empress Wu Zetian.
However, that only applies when dealing with those not of Nazarick.
Fortunately for those who do not serve Nazarick, one can take comfort in the
fact that the mask is very sturdy and will not break easily.
She feels very strongly about her duties as the Guardian Overseer of the Great
Underground Tomb of Nazarick.

Naturally, the fact that she has ears everywhere listening for information goes
without saying.
In addition, she smiles all the time -- to the point where one might say she
does not show any other emotion.
Her smile is nothing more than a poker face to her.
She can also show emotions like anger, grimaces and fake tears.
Her sophisticated lady’s face will not break, even when she is torturing the
fools who oppose her.
By her appearance alone, she is a perfect beauty. Incidentally, she is a slut She is in love with Momonga.