One popular WW2 time travel fiction is 'The Man in the High Castle' by Philip K. Dick. It presents an alternate history where the Axis powers won WW2. Another is 'Time and Again' which has elements that touch on the era of WW2. 'Life After Life' by Kate Atkinson also plays with the concept in relation to WW2, showing different versions of a character's life during that time period.
One popular character type is the time - traveling scientist. They might be interested in studying the scientific knowledge or lack thereof during WW1. For example, they could try to introduce new medical techniques. Another is the adventure - seeking young adult. They see the time travel as an opportunity for a great adventure and end up getting involved in the war in unexpected ways. Also, a war journalist from a different era could be a great character. They could document the events of WW1 in a new light.
Well, '11/22/63' by Stephen King is a great time travel book fiction. It involves traveling back in time to try and prevent the assassination of President Kennedy. 'Outlander' by Diana Gabaldon is also a popular one. It has elements of time travel and a rich historical backdrop, following the story of a World War II nurse who travels back in time to 18th - century Scotland. There's also 'Time and Again' by Jack Finney, which is an oldie but a goodie, with its charming take on time travel to the past.
One idea could be a soldier from WW1 suddenly finding himself in the middle of a WW2 battle. He might use his old - fashioned combat skills in a new and more advanced war setting. For example, his experience with bayonet charges could be a shock to the modern - day soldiers he meets in WW2.
One interesting WW2 time travel fanfiction could be about a modern-day historian who travels back to WW2. They might use their knowledge of the war to change small events and see how it affects the overall outcome. For example, they could prevent a key intelligence leak that would have otherwise given the enemy an advantage.
Some common themes in WW1 time travel fanfiction include the alteration of historical events. This could be something like a time traveler trying to save a loved one who died in the war. There's also the theme of cultural clash. A modern - day person suddenly in the WW1 era would face differences in fashion, language, and values. And a prevalent theme is the butterfly effect. A small change made by the time traveler can have huge and unexpected consequences on the course of the war and history in general.
One interesting plot could be a modern person traveling back to WW2 and using their knowledge of future technology to help the Allies in a covert way, like improving communication systems. Another could be a time traveler trying to prevent a particular tragic event during the war, such as the bombing of a certain city. And there might be a plot where the time traveler has to adapt to the harsh wartime conditions and forms unexpected friendships with soldiers on the front line.
There's also the idea of preventing certain historical events from happening at all. Maybe a time traveler tries to stop the rise of Hitler before he gains too much power. This would involve interfering with the political and social situations in Germany in the early 20th century.
One of the best is 'The Book Thief' by Markus Zusak. It tells the story from the perspective of a young girl in Nazi Germany and how books became a form of solace. Another great one is 'All the Light We Cannot See' which follows a blind French girl and a German boy during the war. And 'Slaughterhouse - Five' by Kurt Vonnegut also stands out as a unique take on the WW2 experience.
A young WW1 infantryman would make a great main character. He could represent the 'old - school' values and combat style of WW1. When he travels to WW2, he has to adapt to the new warfare, and his journey of adaptation could be very interesting to follow.
One possible short story could be about a modern - day historian who accidentally travels back to WW2. He finds himself on a battlefield, witnessing the chaos and heroism. He tries to use his knowledge of the war's outcome to save lives, but quickly realizes that any small change he makes could have huge consequences. For example, he might prevent a key soldier from dying, which then changes the course of a battle and potentially the entire war.