There's such a vast amount of background for the characters in Birds of Prey that I feel uncomfortable writing them, not having read more than a small fraction of it. Unless we're only talking about BoP TV, in which case there's not really enough of it for solid characterisation. Except maybe for Huntress/Harley. Which, now that I think about it, sounds kind of fun.

And yes, some kind of KP/XWP crossover should probably happen.