One idea could be Salem's reaction to the powers and technology in the Worm universe. Maybe she tries to use some of the parahuman abilities or advanced tech to further her own goals in the RWBY world.
A good RWBY Salem fanfic often has a deep exploration of her character. It should show more than just the 'evil villain' side. For example, it could explore her past traumas or her reasons for her actions. This makes her more three - dimensional.
One common theme is redemption. Since Salem is often portrayed as a villain, many fanfics explore the idea of her seeking redemption as a human. For example, she might try to make up for her past wrongs.
A simple way could be through a dimensional rift. A character from RWBY accidentally stumbles into the Worm universe or vice versa. Then they have to figure out how to get back while dealing with each other's worlds' problems.
Fanfiction about Ozma and Salem in RWBY can be quite creative. Some might focus on their love story that turned so sour. It could be about how their initial love was pure but got corrupted over time due to various factors like the power they both held or the interference of others. Others may explore their powers in unique ways. For instance, how Ozma's reincarnation magic could be used differently or how Salem's control over Grimm could be more nuanced. There are countless possibilities for writers to play with in the context of these two characters in RWBY fanfiction.
Yes, in some RWBY fanfictions, Salem can be portrayed as a mother figure. Some authors might explore this aspect to add depth to her character or create unique storylines within the RWBY universe.
Fanfiction about Salem's daughters in RWBY can be really interesting. It might explore their backstories, their relationships with Salem and other characters. Maybe it shows how they develop their powers or their moral stances in the complex RWBY universe.
Salem in RWBY fanfiction is often depicted as the main villain. She has a grand plan that she is slowly working towards. Cinder is a key player in Salem's plans. She is the one who often does the dirty work on the ground.
A lesser - known but really engaging 'human Salem RWBY fanfic' is 'When Salem was Human'. This fanfic imagines Salem's life before she became the powerful and feared figure. It details her early days, her hopes and dreams, and how she might have been corrupted over time.
One interesting plot point could be how Salem's time travel affects the balance of power in the RWBY world. For example, if she goes back in time and allies with certain villains or undermines the heroes in their early days.