Rigallas
Rigallas is a Borg drone from a Borg sphere that was trapped within a Dyson sphere along with the USS Discovery-C. She was granted asylum by LtCmdr Eskyys and is currently being rehabilitated aboard the USS Discovery-C in Science Lab 2. Her pre-assimilation identity was revealed to be an El-Aurian named Jayden, who emerges every now and then, especially under hypnotherapy.
It is unclear if Rigallas/Jayden would be allowed to remain on board for long term.