Character development is a big theme too. Writers often take characters from both universes and give them new challenges and relationships. For instance, a Clone Trooper might form an unlikely friendship with a Transformer, and through their adventures together, they both grow and change. This theme allows fans to explore different sides of their favorite characters and see them in new and unexpected situations.
One popular theme is Vader's struggle with his identity. In the Clone Wars, he's still in the process of becoming the full - fledged Darth Vader we know from the original trilogy. Another theme is his relationship with the clones. Some fanfictions explore how he views them as tools or if he has any sort of empathy towards them.
One popular theme is loyalty. Rex is extremely loyal to the Republic and Ahsoka, and Ahsoka is loyal to the Jedi Order and her friends like Rex. Fanfictions often explore how this loyalty is tested during the Clone Wars.
A common theme is survival. Domino Squad is often put in difficult situations where they have to fight to stay alive. This could be against overwhelming enemy forces or in a harsh, unforgiving environment.
One popular theme is Vader's struggle with his identity. During the Clone Wars, he was still Anakin Skywalker in many ways, so fanfictions often explore his internal conflict. Another theme is his relationship with the Jedi. Since he was on the verge of becoming a Sith, how he interacted with the Jedi during the Clone Wars is an interesting area. And power - his thirst for power and how it grew during the Clone Wars is also a common theme.
Cal Kestis as a young Padawan has also gained popularity in Clone Wars - related fanfiction, even though his main story is set a bit later. But his connection to the Force and his Jedi training, as well as his experiences during the events that led to the fall of the Jedi Order, are often explored in fanfictions that tie in with the Clone Wars era.
One popular theme is Ahsoka's growth. She starts as Anakin's Padawan and through various adventures in the Clone Wars, she matures both as a Jedi and as an individual. Another theme could be her struggle with the Jedi Order's dogma at times. She has her own ideas about right and wrong which sometimes clash with the traditional Jedi ways.
Naruto himself is always popular. In Clone Wars fanfiction, his relationship with his clones can be explored in many different ways. People like to write about his growth as a leader in relation to the clones.
Optimus Prime is often a popular character. His leadership and sense of justice can translate well into the Star Wars universe. He might be seen as a counterpart to the Jedi, with his own code of honor. For example, he could team up with Luke Skywalker, and their combined wisdom and strength could make them a formidable force against the villains.
Anakin Skywalker is often popular. His complex character, with his struggle between the light and dark side of the Force, offers a lot of material for fanfiction. Ahsoka Tano is also a favorite. Her growth from a young Padawan to a more independent figure makes for great storytelling. And of course, Obi - Wan Kenobi, with his wisdom and Jedi skills, is a commonly written - about character in this fanfiction.
Anakin Skywalker is often popular. Gamers like to write about his adventures during the Clone Wars, especially his complex relationship with his padawan Ahsoka Tano. His powerful Jedi skills make for exciting action scenes in fanfiction.