Hush has a full character bio that can be unlocked in Batman: Arkham Asylum, which tells you who he is and what is motives are.
5:42 in video
This creates a sort of paradox in the Arkham timeline as Batman doesn't meet Hush until Arkham City and has no idea of his motives until Arkham Knight.
8;07 in video
5:42 in video
This creates a sort of paradox in the Arkham timeline as Batman doesn't meet Hush until Arkham City and has no idea of his motives until Arkham Knight.
8;07 in video