Specific things about the characters:
1. Harley Quinn - she's totally insane. She'd do anything for Joker and nothing can stop her.
Best way to describe her is through this:
http://prntscr.com/77vptn I want that expression on my veno's.
2. Hawkgirl - she's an outsider came from another world and a warrior.
3. Raven - daughter of a demon bla bla, she's the good evil.
4. Joker - it's the Joker..