Firstly, I do not care the gender of my partner.
The Harley I am looking for is the Arkham game series version, most specifically after Arkham Knight. Sorry, no Harley X Joker. Seeing as he is dead after game 2 of 4. Ever since, Harley thinks Batman killed him and seeks revenge. She even reforms Jokers gang under her rule and becomes a force to be reckoned with.As well, while the batman maybe 'dead' As at the best ending, you see Bruce as batman go into his home and then explosives go off. Yet, the bat family still lives, oracle, Nightwing and the others. So, it means there still is a batman. As well, this is where the story begins, Harley, after overhearing some cops talk about a chemist and an expert on gene modification; she sees the chance at her plan from before of making a new joker. Breaks her and her gang out and finds him. Over time, her old and new personalities combine, she still is the Harley we all know and love, with her intellect and calmness coming back. With my character, while being strangely agreeable with her, tries, but cannot do the impossible. He does help her and her gang in ways he can do however, even while the bat family roam free.
Next is based on Batman Beyond with the Dennis sisters under the joint alias of Dee Dee and granddaughters to Harley Quinn herself. Yet, I want this to be a story about how they learn of their grandmother being Jokers woman herself, how joker died and how it was the bat they did it. Still have not decided about my OC though. I was thinking he could be an engineer or a sort of long time friend to the sisters. Though, only knew them as the twin blonde bombshells and not the makeup and wig wearing Dee Dee of the jokers gang.
That is the condensed version without all the background information. I left out other ideas, but that is for discussion. PM me if interested.