You can start by looking on fanfiction websites like FanFiction.net or Archive of Our Own. These platforms have a wide variety of fan - created stories. Just search for 'Power Rangers in Space crossover' in their search bars, and you'll get a list of relevant fanfictions.
Definitely Andros. He's the leader of the Power Rangers in Space and his leadership skills, as well as his emotional journey throughout the series, make him a great focus. Also, Astronema, as the main villain. She has a lot of layers to her character. She was once Karone, which gives a great opportunity for redemption arcs and exploring the grey areas between good and evil in fanfiction.
One idea could be exploring the backstories of the Power Rangers before they joined the team. For example, how did they discover their potential? Another could be a time - travel plot where they go back to a crucial moment in the history of their planet or the Power Rangers as a whole. Maybe they could meet their predecessors and learn from them.
The 'Power Rangers in Space Original Story' is about a group of Power Rangers who go into space to fight evil forces. They have to face various villains and challenges in outer space to protect the universe.
Some fanfictions crossover Power Rangers in Space with the Transformers. Imagine the Rangers and the Autobots working together against a powerful enemy. The different powers and technologies of both franchises create a lot of interesting plot possibilities.
The leader of the Dark Rangers is often a popular character. They usually have strong leadership skills and powerful dark abilities. For example, a character who can control shadows and use them to attack or defend.
One interesting concept could be the origin stories of the Dark Rangers. Maybe they were once good Rangers who were corrupted in some way, like being exposed to a powerful dark energy. Another concept could be their unique powers compared to the regular Power Rangers. Their powers might be more shadow - based or have a connection to dark magic.
In fanfiction, a story about Tori from Power Rangers being pregnant could explore various themes. It might focus on how she balances her ranger duties with the pregnancy. Maybe her fellow rangers would be very protective, like they'd take on more tasks to ensure her safety. Also, it could show her emotional journey, from the initial shock to acceptance and preparing for motherhood.