Darwin grew up in a secret military facility as part of a team of children genetically designed to become super soldiers. His skin color and hair are unintended side effects from the genetic engineering.
Darwin had a hard time fitting in at the facility, and at the age of 10 he ran away. He lived in the street for a couple of years and eventually got picked up by PURGE. With no social-ID and being an illegal GMI (genetically modified individual), he might have been heading for termination or lifelong imprisonment, but a high-ranking female agent named Amanda took pity on Darwin and pleaded with PURGE directors to let her raise the young boy as her own. PURGE saw the potential in Darwin’s skills, and he was raised by Amanda to become an agent.
Since he's not a legal citizen, Darwin has to reside at the PURGE headquarters. He's talented and responsible in his job as a field leader, but his spare time is a different matter. Darwin prefers to lead a carefree life with plenty of partying, drinking and women. He's very self-confident and charming, but he is also a womanizer and generally spoiled and full of himself.