Missandei

Missandei was a polyglottic slave from Naath, before being freed and becoming a close advisor to her liberator, Daenerys Targaryen. Originally from Naath, she was captured by Astapori slavers at a young age and eventually found herself in the possession of Kraznys mo Nakloz, serving as his translator. She was eventually freed by Daenerys Targaryen just prior to her conquest of Astapor, and went on to serve her as one of her closest advisors and more loyal subordinates during Daenerys' campaign to take, emancipate, and later reign over Slaver's Bay, as well as her later campaign to take the Iron Throne from Cersei Lannister until she turned her attention north to face the advancing Army of the Dead. Missandei didn't survive the Great War, perishing during the Battle of King's Landing.