First, you need to study her character thoroughly. Watch the source material multiple times to understand her traits, like her determination and her combat skills. Then, come up with an interesting concept. It could be something like 'Mercury Black in a parallel universe where she has different abilities'.
One popular Mercury Black fanfiction could be those that explore her backstory in greater detail. For example, some might focus on her life before she became the character we know, delving into her upbringing and the events that shaped her personality.
One popular theme is the origin story of the silver eyes. Writers might explore how Mercury Black came to have such unique eyes, perhaps tying it to a special power or a family heritage.
There are fanfictions that might focus on Mercury Black's training. In these stories, we could see how he hones his skills, perhaps in a more detailed and unique way than what's shown in the original RWBY series. It could also include some epic fight scenes where he showcases his abilities against new opponents or in different scenarios.
You can try looking on fanfiction platforms like Archive of Our Own (AO3). It has a vast collection of fanfictions on various topics, including ones related to characters with specific traits like Mercury Black and silver eyes.
In a RWBY Mercury Redemption fanfiction, his relationships can play a crucial role in his development. If he forms strong bonds with the good guys, like befriending Jaune or Weiss, they can influence him to change. Their different values and outlooks on life can gradually rub off on him, shaping him into a better person.
It shows his vulnerability. In these fanfictions, Mercury's past abuse makes him more than just the tough - guy character we see in the show. We get to see the cracks in his facade.
Another place is FanFiction.net. There are many RWBY fans who post their fanfictions there. However, the quality can vary. So, you might need to read the summaries and reviews to find the good ones about Mercury Black. Some of the popular RWBY fanfiction writers also post their work there.
Mercury herself is of course a central character. Often, her friends or allies from the original story also play important roles. For example, if it's in a certain universe, characters like Sailor Moon might be in the fanfiction trying to save or stop Mercury.
Another aspect could be a friendship story. Naruto, with his never - give - up attitude, might inspire Sailor Mercury to be more assertive in her battles. They could team up against a common enemy that is threatening both their worlds. This would bring out interesting character dynamics as they learn from each other's strengths.