Cywren Caster ia the main character in A Fallout Tale.
Cywren has shown to be very adventurous and intelligent, shown in the first episode when she was only 1 and could already manually unlock her baby gate, and hack terminals with ease (Revealed by Venturian when she gets fed up with his lack of knowledge and picks the codes herself.) She is also shown to be very eloquent and charismatic, seeming to get herself out of any situation if she has the ability too. While very eloquent and intelligent, these seem to be balanced out by her lack of skills with some guns, and lack of strength, yet she appears to be getting stronger. Despite her intellect she really fails when it comes to history as she called a Tokugawa samurai Ghenghis Khan even though Ghenghis was a mongolian. This is understandable as she was born in a time in which survival is more important then learning the past though this does not excus Venturian himself for not knowing this.
Cywren seems to have a very big heart and very selfless, seemingly distressed when she couldn't save Lucas Simms, and also very reluctant to take rewards, usually saying "You don't have to pay me anything". Not most would consider Cywren 'brave' but she is definitely trying, considering the facts that even though she was afraid to deactivate the bomb in Megaton and of the Super-Mutants, she managed to deactivate the nuke and save the people in the Police Headquarters. She is also willing to give her life to save the world, which was shown when she sacrificed herself and was exposed to 5000 rads of radiation to activate the Purifier. (Fawkes/Copper didn't know how to use it, and even if he did his fingers were too big to press the buttons, anyway.) And since she didn't know that she was part Time Lord, she thought she would actually die.
But in time she has become restless, irritated, impatient and has grown unaffected by the deaths of people that were not in her circle of friends (example would be Alex Dargon). She has also grown attached to objects more so than humans. Also shown when she was mean to Sally when they were abducted by aliens and went out of her way to show that she didn't want help from a child. However, her angry nature hides a kind heart, since she respected Sally in the end.
It can be assumed that her angry nature was a result of inability to save her Father from death which then a few Enclave Eyebots proceeded to mock with their patriotic music. This would make even the kindest person bitter. But she was also a very easy to annoy and irritate before this as seen in almost every episode.