Common themes in 'This is War Star Trek' fanfic are quite diverse. The idea of unity in the face of a common enemy is a big one. Different species and crews coming together to fight a greater threat. Technology also plays a role as a theme. How new technologies are developed or used during the war. And there's always the underlying theme of hope, that even in the darkest of times during the war, there is still a glimmer of hope for a better future in the Star Trek universe.
One popular platform is Archive of Our Own (AO3). It has a vast collection of Star Wars fanfic. Another is FanFiction.net which also has a large number of Star Wars - related stories.
One popular trope is the 'fish out of water' situation. Thor, being from Asgard, is in the completely different universe of Star Wars. His reactions to the new technology, Force, and different species can be really interesting to read.
Character adaptation is also a big theme. Characters from both universes have to adapt to the new rules and environments of the other. For example, how a Jedi would deal with the Locust Horde from Gears of War or how a Gears of War soldier would handle a lightsaber. This leads to a lot of interesting character development stories within the fanfics. And often there's a theme of cooperation or conflict between the two universes' forces, which drives the plot forward.
In this kind of fanfic, the characters would play crucial roles. Captain Kirk, for instance, could be in a difficult position. He has respect for the Vulcans like Spock but also has to protect the interests of humanity. He might try to negotiate peace, but some hard - line elements on both sides could make it extremely difficult. And on the Vulcan side, characters like T'Pau might also be involved in decision - making regarding the war.
Sure. You can start by looking on fanfic websites like Archive of Our Own. Just search for 'This is War Star Trek' and you'll find a variety of stories written by different authors. Some might focus on the battles in the Star Trek universe, while others could explore the relationships between characters during a time of war.
Anakin Skywalker is really popular. His complex character, with his struggle between the light and dark side, offers a lot of room for fanfic exploration. Ahsoka Tano is also a favorite. Her journey as a Jedi apprentice and her relationship with Anakin are often explored in fanfic.
One interesting concept could be exploring the backstories of the clone troopers in more depth. Maybe delving into their individual personalities and how they deal with the war. Another could be alternate endings to certain battles in the Clone Wars, like what if a different strategy was used at the Battle of Geonosis.
When the Star Wars spaceships visit the world of Steven Universe. Just imagine the Millennium Falcon landing in Beach City. The reactions of the local characters like Steven and his friends would be hilarious. And the pilots from Star Wars would be equally amazed by the strange and beautiful world of Steven Universe.
The high - stakes nature of the stories. Just like in both the original Star Wars and Infinity War, the fate of the galaxy (or universes) is at stake. This makes for really intense and engaging reading. Fanfic authors often come up with creative ways to raise the stakes even further, like introducing new super - powerful villains or having the Infinity Stones corrupt some of the Star Wars characters. It keeps the readers on the edge of their seats.