Grover might also be involved. His ability to sense emotions and his connection to nature could play a role. He could be the one to initially sense Padme's arrival or help her understand the more magical and nature - related aspects of the Percy Jackson world, like the power of the gods and the spirits of the forest.
Obi - Wan Kenobi would be one. He's Anakin's master, and in the fanfiction, he might suspect something about their relationship and have to decide whether to support them or uphold the Jedi Code.
Draco Malfoy would be a likely character. Given his Slytherin status, he would likely have a complex relationship with Percy. He might start off as hostile, seeing Percy as an outsider, but then they could end up having to work together for some reason.
Percy himself, of course. Given his leadership skills and powerful abilities, he would be the first to step up and face the Pillar Men. His ability to control water could be a great asset or a hindrance depending on the situation.
In some fanfiction set in a more peaceful time, they might interact with a lot of tender moments. They could have picnics and long walks, just enjoying each other's company and having deep conversations about their future.
Issei would be really interesting. He's the main character in DxD and has his own set of powers and a rather unique personality. His pervy nature would contrast with Percy's more heroic and sometimes serious demeanor. Their interactions could be both comical and lead to some great character development for both.
Well, Annabeth would definitely be one. She's always been by Percy's side, and in this fanfiction, she might be a bit worried about Percy being the champion of Nyx. She could be trying to help him while also being cautious of Nyx's motives.
Naruto would likely interact with Padme in a very enthusiastic way. He's always eager to make friends and allies. He might be in awe of Padme's grace and political power at first. Padme would probably be cautious but intrigued by Naruto, given his unique abilities as an Arc Trooper combined with his ninja skills.
One idea could be that Padme somehow gets transported to the Percy Jackson universe. She could use her diplomatic skills to help resolve a conflict between the demigods and a new, powerful enemy. Maybe she teams up with Percy and they combine their unique abilities to defeat the foe.
It could be Percy and Black Widow. Natasha is a master of reading people, and she'd notice Percy right away. She might approach him in a more stealthy way compared to the others, trying to assess if he's a threat or an ally. And Percy, being used to danger, would be on his guard at first, but then start to trust her as she shows her good intentions.
Besides Padme, Anakin is a key character. Their love story is a big part of the Star Wars lore. Additionally, there could be characters from Padme's home planet who play important roles, like her family members or advisers. They might influence her decisions and actions throughout the novel. Also, some Jedi might be involved as they are often intertwined with the political and personal affairs in the Star Wars universe.