Harley could be developed by giving him more technical skills. Maybe he starts to build his own advanced gadgets. This would show his growth and dedication to being like Iron Man.
In the fanfiction, Harley's character development can be quite diverse. Sometimes she starts as a meek psychologist who is slowly corrupted by Joker. As the story progresses, she becomes more assertive in her own way, even if still under Joker's spell. She might learn to stand up to him a bit more while still being in love with him.
Yes, Harley exists in the comics related to Iron Man.
Harley Quinn's character can be developed by showing her struggle with her identity after the Joker's death. In Arkham Knight fanfiction, she could start to question her loyalty to the Joker's legacy. Maybe she begins to form her own moral code, separate from the chaos the Joker brought.
One common theme is mentorship. Iron Man often takes Harley under his wing, teaching him about technology, heroism, and responsibility. Another theme is adventure. They usually go on some sort of exciting mission together, like fighting against a new super - villain or exploring a mysterious technology.
Their relationship could develop through shared experiences. For example, they could go on heists together and during those times, Joker could start to see Harley in a different light. He might notice her intelligence and loyalty more and more.
One great 'Iron Man Harley fanfiction' is 'Harley's Adventures with Iron Man'. In this fic, Harley, with his brilliant mind, teams up with Iron Man to solve a series of high - tech mysteries. It's full of exciting action scenes and the dynamic between the two characters is really well - written.
Their relationship could be further developed by having them face a major crisis together. For example, if they both lose their memories but still feel a strong connection to each other. They would then have to rediscover their love and who they are as individuals. This would deepen their bond in a new and unique way.
Harley Keener does not become Iron Man in the comic universe. The storylines and character developments don't lead in that direction. He might have his own unique adventures and contributions within the comic world, but not as Iron Man.
It could be a rival tech mogul. Someone who is jealous of Iron Man's success and wants to use Harley's sister as a way to get to him. This villain might try to kidnap her to force Iron Man to give up his technology secrets.
Perhaps there's a plot where Harley's sister has to be protected by Iron Man. She might be in danger because of her relation to Harley or some secrets she holds. And in the process, they form a special bond. Iron Man might use his advanced suits and technology to keep her safe from various threats, like villains who want to use her as a leverage against Harley or Stark Industries.