Derek is a young werewolf, and a subject in the Genesis II project.
Derek was a subject in The Edison Group's experiments to make life better for supernaturals by genetically manipulating DNA in vitro to suppress what they deemed as weaknesses in a supernatural and strengthen what they believed to be good traits. It is not known if his biological mother was a willful subject but it is known that she seduced a werewolf, Zachary Cain, to get pregnant and her fate after she gave birth is unknown. He lived in an institutional setting while he was with The Edison Group. Derek, along with three other werewolves, or pups, were monitored and carefully watched at all times.
The Edison Group had been Derek's "home" until he was about 5 years of age, when the three other pups cornered a nurse and attacked her. While the other pups were terminated, Derek was taken by Christopher "Kit" Bae who, at the time, was a member of the Edison Group. Christopher was the father of another subject, Simon Bae who is a sorcerer. Christopher had taken de-facto custody of Derek when he was about 5 years of age. A while after that, the group asked Christopher to deliver a threat to some of his ex-colleagues. Christopher refused, warned his ex-colleagues, and fled with Derek and Simon. From that moment on Derek became a true son to Kit and brother to Simon. Derek feels an enormous amount of gratitude and love for his family and would do anything to protect them. Simon especially, as he is not only Dereks brother but also his best friend.
Derek has had behavioral problems, which began in seventh grade. He was never an outgoing or a cheerful child, and he had become increasingly sullen. His withdrawal was punctuated by bouts of misplaced anger, and often culminating in violent outbursts. Although Derek has a very big temper and is seen as violent, he is also extremely smart and reads several college-level subjects at the age of 16. It is mentioned that he excels in both mathematics and science. He is usually put in detention for correcting a teacher or being seen as sarcastic, though he was just being overly polite because of his stay at The Edison Group lab as young child (this is all shown in Dangerous). Derek has been able to avoid being expelled and other serious disciplinary action until an altercation described by witnesses as "a normal school yard fight." Derek had "violently attacked" three youths in what officers suspected was a chemically fueled rage.
He is very protective over the people he cares about, but could care less about others. As a son to Kit he did everything in his powers to be a good son and in The Reckoning Kit would jokingly say he would rather have a dozen of Derek than one of Simon. Derek, being a werewolf, has enhanced hearing, increased strength, agility, senses, and other common werewolf powers. At this point in time it is unclear what the scientists modified in his DNA. The only known difference that can be discerned from other werewolves is the fact that Derek was able to transform at a younger age than most natural born werewolves. This may or may not be due to the genetic modification as it is not unheard of, just uncommon.
The other possible modification is a reduction in the urge to kill, which is something most werewolves struggle with since they see humans and other creatures as prey (especially when they run away). Of course, most werewolves can control this urge and view human killing as taboo but Derek never had the urge to begin with leading the reader to believe it may have been removed. He and Chloe show growing feelings for each other, and begin dating at the end of The Reckoning. In the "Rising" he becomes friends with Daniel.