Very little has been revealed about the Doctor's past before their amnesia. At the very least, they used to have a doctorate in neurology and extensively researched oripathy. The Doctor was once one of the key figures in Babel, Rhodes Island predecessor, and have the same role they are in present time, more of a tactician than a researcher, if far more ruthless.
![Arknights [Book Of Randomness]](https://img.wattpad.com/cover/243733667-64-k208001.jpg)