A plot could involve a magical object that has the power to bring people from different universes together. Ziva David gets pulled into the Harry Potter world because of this object. At first, she is a bit of an outsider, but Harry Potter takes an interest in her. As they work together to figure out how to send Ziva back or if she should stay, they fall in love. Along the way, they face challenges from both the Muggle - hating pure - blood wizards who see Ziva as an oddity and from the threats in Ziva's own world that might be seeping into the wizarding world through the same magical object that brought her there.
One possible plot could be that Harry discovers his true mother is Ziva David through some magical means. Maybe a powerful spell reveals his hidden heritage. He then has to deal with the fact that he has a connection to two very different worlds - the wizarding world of Harry Potter and the world of Ziva David, which might be something like the world of NCIS in the original show. He could struggle to balance the two identities and the different skills and knowledge from each world.
Yes, there are some out there. You can start by looking on popular fanfiction websites like FanFiction.net or Archive of Our Own. Just search for 'Harry Potter and Ziva David Romance' in their search bars and you might find some interesting stories.
It could be a combination of Voldemort and one of Ziva's enemies from her own world. Imagine if Voldemort made a deal with an enemy of Ziva's, like a powerful terrorist or a corrupt politician. They would team up to try and take over both the magical world and Ziva's world.
One idea could be that Ziva David somehow gets transported into the Harry Potter universe. She could use her combat skills and intelligence to help the Order of the Phoenix in their fight against Voldemort. Maybe she teams up with Hermione to outwit Death Eaters with their combined knowledge.
The main antagonists could still be the Death Eaters. Since they are the traditional enemies in the Harry Potter universe. They would see Harry, even as the son of Ziva David, as a threat to their dark plans. They might target him not only because of his connection to Harry Potter but also because they fear the unknown elements that Ziva's heritage could bring into the fight against them.
Obviously, Harry Potter and Ziva David are main characters. Harry, with his knowledge of the wizarding world, and Ziva, with her worldly and combat - trained skills. Their interactions would be the core of the story, whether they are friends or rivals.
Another concept could be the interaction between Ziva and the different houses at Hogwarts. For example, if she were sorted into Gryffindor, how would she bond with the brave and daring students there? Or if she were in Slytherin, how would she use her cunning and ambition in the context of the wizarding world? It could lead to some really unique storylines.
Well, the plot could start with a magical accident that causes a rift between the two universes. Elsa and Harry are both drawn to this rift and end up in a strange in - between place. There, they have to rely on each other to survive. Elsa's ice powers and Harry's magic complement each other in this new environment. As they face various challenges together, they begin to see each other in a new light and develop romantic feelings.
Well, it could be about all the preparations for their wedding. Maybe they argue over the guest list, like Tony wants to invite all his old buddies from the agency and Ziva has her own list of Mossad contacts. Then there could be a really sweet moment when they choose their wedding rings, with Tony picking out a simple but elegant one for Ziva, and Ziva finding a cool ring that has some meaning related to their adventures together.
Love and romance are very common themes. Since their relationship on the show had so much potential, fanfiction often explores their romantic feelings for each other more deeply.