Tome is an assassin in training, in service to the Raven Queen. Kenku monks from her monastery are gifted, telepathically, with the true name of the Raven Queen - which would normally be truly valuable information; however, given the Kenku speech impediment of only being able to mimic rather than speak, the secret is tightly guarded. As a point of fact, the monks are given the Raven Queen's true name for one purpose - should they ever hear it spoken by a non-believer, they know to swiftly silence the threat to their matron.
Monks are a lot of fun - I played one way back in the 5th Edition beta playtest. Being a Kensei gives me that classic "wandering samurai" vibe (super cliche and corny, but a total blast to play). The Kenku Mimicry is also constant trial to RP, but I enjoy the challenge.
The kanji on her banner is something along the lines of "Crow God" - it's almost certainly incorrect, but it was as close as I could muster!