Unnamed Assassin

"Blasphemer! You are not worthy to speak of the great Ra's al Ghul!"

―The Unnamed Assassin

Before Arkham City Incident
The Unnamed Assassin is one of Talia al Ghul's personal guards who were assigned to escort Talia into Arkham City and to keep track of the growing chaos. At some point, she was ambushed the Penguin's Henchmen and, despite successfully killing eight of them, was eventually incapacitated.

"Now this little minx is a real puzzle. Where did she come from? How did she kill eight of my men before we managed to hold her down and beat her into unconsciousness? All I know is... I like her pajamas."

―The Penguin's recording on her display case.

Already injured from her previous capture, the Assassin then endured several weeks (possibly months) of captivity, and was stuck in one of the Penguin's glass display cases as part of his collection. Despite being questioned several times about her origins, the assassin remained tight-lipped and chose to remain completely silent. Growing frustrated with the lack of information, as well as being preoccupied with the Arkham Gang War, Cobblepot eventually lost his patience with her and instead opted to just leave her confined to her case where she remained.

Over time the Assassin grew more and more docile to the point where she refused to speak a single word and even seemingly became comfortable with her captivity.

At some point, Robin entered Arkham City disguised as an inmate. He passed the display where the assassin was kept, and noted that she looked real enough. The assassin's eyes followed him as he moved away from the display.

Arkham City Incident
On the night that Protocol 10 was finally ready to be commenced, the Assassin's solitude was interrupted when a masked vigilante broke into the Museum to free one of her fellow captives. Despite the obvious chance of freedom, the Assassin instead opted to ignore the events that were happening outside her case and started to meditate.

Eventually when the vigilante mentioned the name of her mistress' father, the Assassin came to life for the first time in months, and using her renewed strength, attempted to shatter her way out of her glass case. That proved successful, though she ended up cutting herself on some of the glass. Declaring that the vigilante was not worthy speak of her master, the Assassin then fled from the Museum with the intention of finding her mistress and warning her of the potential danger that the vigilante could bring upon them.

The vigilante, however, was able to follow the Assassin with no problem by tracing her blood, which prompted the Assassin to ambush him. After she successfully knocked the vigilante to the ground, the Assassin warned him to stop following her unless he wished for a gruesome death and that the only reason that he was even still alive right now was because her master wished it.

Before the Assassin could threaten him further, she herself was then ambushed by the vigilante's apprentice. Before further violence could proceed, a group of the Assassin's fellow League of Assassins appeared to help their sister. Outnumbered and not willing to risk his apprentice's safety against opponents more skilled then he, the vigilante ordered him to stand down and reluctantly agreed to stop following the Assassin, though not before he secretly placed a tracking device on the Assassin's shoulder.

Eventually making his way into Wonder City, the vigilante was overcome by a sudden outbreak of sickness from a disease which had been planted inside him earlier that night by the vigilante's greatest enemy. While incapacitated, the vigilante was suddenly surrounded by a squadron of Assassins. Furious that the vigilante had not heeded her warning, the Assassin prepared to cut his head off only to be stopped at the last second by her mistress who had had a past with the vigilante.

When asked how he had managed to find them, the vigilante revealed that he had used a tracking device which he had planted on the Assassin's shoulder, of which she had remained unaware. Clearly angered by this lack of foresight on the Assassin's part, Talia brushed away the Assassin's attempts to explain herself, and said only that she would deal with her later.

It's unknown what became of the Assassin after that, although it's unlikely that she was one of the casualties of Protocol 10 and it could be assumed that she remained underground for the rest of the night.

It's also likely that Talia (assuming that she was resurrected) punished her for her poor performance as she had promised earlier. Although in what way and to what extent remained unknown.

Appearance
The Assassin had the standard appearance of all the League of Assassin members that appeared in Arkham City.

Quotes

 * "Blasphemer.You are not worthy to speak of the great Ra's al Ghul!"
 * "You only continue to live because the great Ra's al Ghul allows it!"
 * "Call him off!"
 * "Do not follow us!"
 * "You should have listened to my warning! There are no friends to save you down here!"
 * "Please, mistress... He tricked me!" (Talia al Ghul)

Trivia

 * To date, her actual name was not revealed.
 * It's unknown what became of her after Arkham City.
 * She was voiced by Kari Wahlgren.