@rac95: I'm fully aware of who Leon is, as I have played several RE games. With that being said, I've seen nothing from him that a normal street level superhero could not accomplish. I see no reason why he has such an advantage in this fight.
@anthp2000: Unfortunately, I don't have scans on hand, but I do know that it happened in her solo series. The second volume if I'm not mistaken.
The fact that people think that guns are a threat here are pretty funny. Selina has deflected a bullet with the hilt of her whip. She also took a dart out of the air with her whip, and the dart was shot out of a gun. Not to mention she dances around bullets often.
With that being said, If Catwoman won't have a problem, that goes even more so for Harley, who is faster and more agile.
As for the fight, I don't know enough on Leon to say.