His friends like Hermione and Ron could also be important characters. Hermione might use her intelligence to help Harry during the pregnancy and after the birth, while Ron could provide some comical relief with his typical reactions.
Another idea might be the nature of the cubs. Are they part human, part magical creature? And how do they inherit Harry's traits and powers? This could lead to many adventures as Harry raises them.
Hermione would probably be involved. She's always been there for Harry in the original series, so in this fanfiction, she might be the one trying to find a way to reverse the situation or help Harry through the process. She's smart with potions and magic, so she'd be a key character.
Padme herself is obviously a main character. She is the one giving birth after all. Her baby, which could be Luke or Leia in the Star Wars context, is also an important part, even if not fully developed yet at the time of birth.
The 'bro' could be another important character. It might be a friend of Harry's like Ron or Hermione, who has been transformed into a 'bro - like' figure for the purpose of this fanfic. There could also be a healer or a wizard who is an expert in the strange magic that caused Harry to give birth. Maybe Dumbledore could also make an appearance to guide Harry through this difficult situation.
The Cullen family members are also key. Carlisle, as the patriarch of the vampire family, would be involved in the medical aspects of Bella's pregnancy and birth. Esme, with her motherly nature, would be there to support Bella. Alice, with her ability to see the future, could be crucial in predicting any problems during the birth. Jasper, too, would be part of the family's support system, even if his power of influencing emotions might not be directly related to the birth.
Aphmau herself is obviously a main character. Aaron is often another important character as he is her significant other in the Aphmau series. He would be there to support Aphmau during the birth process. Also, her friends like Katelyn and Kawaii - chan might be present, offering their own unique forms of help and adding to the story's charm.
Obviously, Harry and Draco are the main ones. Harry, with his kind heart and strong magic, and Draco, who has his own complex personality. Their relationship in this fanfiction is the focus, and the act of Harry giving Draco a hickey is something that will shape their interactions and the story around them.
It could be some other wizard who Harry had an unexpected encounter with. Maybe it was a wizard who was secretly in love with Harry and used some sort of love - related magic that had an unforeseen consequence.
It could be that the father is an unknown wizard who Harry had a brief encounter with. Maybe it was a one - time magical connection that led to the pregnancy.
Obviously, Clary herself is central. Then there's Jace, her love interest. He would be very involved, probably being there for her throughout the pregnancy and during the birth. Simon might also be there. As Clary's best friend, he would offer his support in his own way, perhaps with some comical moments to lighten the mood.