What if Harley Quinn goose back in time and meets Clark in Smallville and become friends?
What I mean is that Lex Luthor try to go back in time. The justice league try to stop him. But Harley Quinn stop him. But Harley end up going back in time.
It sounds like an interesting fanfic! Harley and Clark are both very open, very upbeat people, so if Harley was not under the Joker’s influence I think they have the potential to get along. I imagine the dynamic would be similar to that of Lex and Clark in the ‘Smallville’ tv show, with Harley feeling tempted to darkness and Clark wanting to pull her back but not at the expense of his own morality.
Think of it as it coming from the future. Like today Harley Quinn and today Lex Luthor. Also today Justice League. Lex is trying to get the legion ring from the Justice League vault. Then Harley Quinn get him from behind accidentally make the ring go in the air. Then it fall on her finger.