Martian Manhunter would be a great character to include. His shape - shifting abilities and telepathy could be very helpful in the fight against the bad guys. He could also serve as a mediator between Wonder Woman and Superman if they ever have differences in opinions, given his calm and collected nature.
The Flash could also be included. His super - speed could be useful in various situations, like delivering a crucial message or distracting the enemy. He could also provide some comic relief with his quick - witted remarks and his eagerness to prove himself among the more powerful heroes.
Steve Trevor could be a great addition. His relationship with Wonder Woman adds an element of human connection. He could be caught in the middle of the conflict between Wonder Woman and Cheetah, or he could play a role in helping Wonder Woman understand Cheetah better. For example, he might have some insights from his military experience that could assist in dealing with Cheetah.
Harley Quinn could be a great addition. She has a complex relationship with both Poison Ivy and Batman. Her chaotic nature could add a lot of twists to the story. Another character could be Alfred. His wisdom and loyalty to Batman could provide interesting interactions when dealing with Ivy.
Well, Kikyo is an obvious choice. Her connection to both Inuyasha and Naraku is deep. Her presence could create a lot of tension, especially since Kagome is often compared to her. Shippo could also be in the fanfiction. His cute and innocent nature could contrast with the dark nature of Naraku. And Kaede, the old priestess, could offer her guidance and wisdom regarding the strange relationship between Naraku and Kagome.
Edward could be a good addition. Since he has his mind - reading ability, it could create some interesting interactions with Alice's visions. Also, Bella could be included as she has a connection to both Alice and Jasper through Edward. Her human perspective could add a different dimension to the story.
Lois could be a great addition. Her relationship with Peter and her reactions to his antics with Quagmire can add a lot of drama. Also, Cleveland. His calm and collected nature contrasts with Peter and Quagmire's craziness. His interactions with them can lead to some really funny moments.
I think Hinata could be a great addition. He could be the comical sidekick who always gets into funny situations and in the process, either helps or hinders Usui and Ayuzawa's relationship. Another good character could be Ayuzawa's mother. Her presence could add some family drama, like she might not initially approve of Usui for her daughter.
Narcissa Malfoy could be an interesting character to include. She might be torn between her loyalty to the Malfoy family traditions and seeing the potential good in Harriet for her son. She could play a role in bringing Harriet and Draco closer, perhaps by inviting Harriet to the Malfoy manor under some pretext, which would be a very tense and interesting situation.
Santana could be a great addition. She could be Rachel's best friend who gives her brutally honest advice about married life. Like when Rachel has a fight with Jesse, Santana would be there to say something like 'Girl, you need to put your foot down or he'll walk all over you.'
Edward could also be included. His relationship with Rosalie as her adoptive brother and his complex feelings towards Jacob could create a lot of tension and drama. He could be a voice of reason or a source of conflict, depending on the direction of the fanfiction.
Jacob could be a great addition. He has a complex relationship with Bella in the original series. In fanfiction, his interactions with Charlie could be explored further. For example, how Charlie reacts to Jacob's wolf - shape - shifting abilities and his love for Bella.