Harley Quinn is an anomaly in comic books because ... where Harley attempts to break into Arkham Asylum to kill the Joker, only to change her mind and decide to help him escape instead.

The Arkham games are quite heavily involved in the evolution of Harley Quinn, and part of that comes ... exclusive to the PS3 ...

However, outside that universe, Harley Quinn also debuted the fifth ... Harleen was a psychiatrist at Arkham Asylum who formed an unhealthy relationship with The Joker to the point she believed ...