One possible character could be Mystique. Since she has a connection to Rogue in the X - Men lore, she might be involved. Maybe she's initially against Rogue joining the X - Men and tries to stop it. Another could be Magneto. He might see Rogue as a valuable asset and try to recruit her for his Brotherhood of Mutants, creating a conflict between the X - Men and Magneto over her.
One great X - Men Rogue fanfic is 'Rogue's Redemption'. It delves deep into Rogue's character, exploring her struggles with her powers and her place among the X - Men. The story has a great plot that keeps you hooked from start to finish, with interesting character interactions, especially between Rogue and Gambit.
The age of Rogue in X-Men comics isn't fixed. It changes based on the context and the era of the comics. Sometimes she's shown as a young adult, while in other storylines, her age might be presented differently.
The X-Men are part of the Marvel Comics lineup. They have their own unique place within the Marvel multiverse, with a dedicated fan base and a significant impact on the comic book world.