Apollo is always a popular choice. He's a powerful demigod with abilities related to the sun, music, and prophecy. You could write about his role in the wars, maybe how he uses his musical talents to inspire his allies or his prophetic visions to foresee important events.
Athena is another great character. She's known for her wisdom and strategic skills. A fanfic could focus on how she plans battles and outwits the enemies in the Demigod Wars. She could also be mentoring a young demigod, passing on her knowledge.
Andy is a great choice. He's a well - known and likeable character in the game. His growth as a commander and his relationships with other characters can be explored further in a fanfic.
Ahsoka Tano is a very popular choice. She has a rich backstory from the Clone Wars series, and her relationship with Anakin Skywalker gives a lot of room for exploration. You could write about her solo adventures, her growth as a Jedi, or her experiences during the war.
Amuro Ray is always a popular choice. His skills as a pilot and his complex character make him a great addition to any fanfic. He has a lot of backstory from the Gundam series which can be incorporated into the Super Robot Wars fanfic world.
One of the most popular characters to feature in such fanfics is Yoda. His immense power and wisdom, along with his unique way of speaking, can create some really interesting stories. Additionally, Padmé Amidala can be a great character to include. Her relationship with Anakin and her political influence in the Republic can be explored in many ways. Then there are the clone troopers in general. Each clone has his own personality, and writing about their experiences during the Clone Wars can be very engaging.
Cal Kestis is an obvious choice. He is the main character of the game, so there are a lot of story possibilities centered around him. BD - 1 is also a popular character. A fanfic could focus on the relationship between BD - 1 and Cal, or BD - 1's own adventures.
In Star Wars Rebels fanfic, the Inquisitors are often used as antagonists. Their dark side powers and their pursuit of the remaining Jedi make them interesting characters to write about. Also, Chopper, the droid, is a fan favorite. You can write humorous stories about his antics and his loyalty to the crew of the Ghost, or more serious stories about how his unique abilities have saved the Rebels in difficult situations.
For Star Wars, Rey is also a popular choice in these crossovers. Her strong connection to the Force could be explored in relation to the Light in Destiny. She could team up with a Hunter from Destiny, and together they could go on a quest to defeat some new evil that combines elements from both universes.
Definitely Clone Captain Rex. He is a fan favorite among Clone Wars fans. He is a skilled leader, has a strong sense of loyalty, and his interactions with the Jedi and other clones are really interesting. Also, Darth Maul makes for an exciting character in fanfic. His return in the Clone Wars series added a new layer to his story, and his thirst for revenge and power can be explored further in fanfic.
Master Chief from Halo is often a popular choice. His badass, no - nonsense attitude and his combat skills make him a great character to put up against the Jedi or Sith in Star Wars. In Star Wars, Darth Vader is also a very popular character to include. His iconic look and his powerful Force abilities can create some really intense scenes when pitted against Halo characters.
Luke Skywalker is a common character in Star Wars zombie fanfics. He has the power of the Force and the will to fight for good. In a fanfic, he could be on a quest to find a cure for the zombie plague that has befallen the galaxy. Yoda might also be featured. His wisdom and small - yet - mighty presence can add a unique element. He could be guiding other characters on how to deal with the spiritual aspect of the zombie threat, as if the zombies are some sort of dark side manifestation.