One common theme is redemption. Sometimes, fanfictions will explore Cinder's character in a way that she is redeemed through a relationship that involves kisses. Another theme could be forbidden love. Given Cinder's role as a villain in RWBY, a relationship with a hero or other character might be seen as forbidden, and kisses play a part in that complex dynamic.
Power dynamics is also a frequent theme. Cinder is a powerful character, and in fanfictions with kisses, there might be an exploration of how power is balanced or unbalanced in a relationship. For example, a kiss could be a moment of vulnerability for her or a way to assert dominance. Additionally, themes of secrecy often come up. Since Cinder is a villain, any relationship she has might need to be kept secret, and kisses in these secret moments add an element of intrigue.
One common theme is redemption. Many fanfictions explore the possibility of Cinder finding a way to atone for her actions. Another is power - seeking. Since Cinder is often depicted as power - hungry, fanfictions may expand on her pursuit of more power. And there's also the theme of identity, as she tries to figure out who she really is beneath all the villainy.
A common theme is power and ambition. Cinder is a very ambitious character in RWBY, and many fanfictions explore her drive for power further. For example, she might be on a quest to gain even more power than she already has in the show. Another theme is redemption. Some fanfics like to imagine if Cinder could be redeemed and what it would take for her to turn away from her evil ways.
You can start by looking on popular fanfiction platforms like Archive of Our Own (AO3). Just search for 'rwby cinder kisses' in the search bar, and it should bring up relevant stories. Another option is Fanfiction.net, but AO3 generally has a wider range of works and better tagging system for finding specific content like this.
The exploration of their backstories together is also a theme. Writers may create scenarios where Ruby and Cinder's pasts are somehow intertwined, perhaps revealing secrets that change their relationship in the RWBY universe.
Power. Often, Cinder's power is explored to an extreme in these fanfictions. Her already formidable abilities are pushed further, making her even more of a force to be reckoned with.
Another theme is often the forbidden nature of the relationships. Cinder is a complex character, and in many fanfictions, her relationships are seen as something that goes against the norm, whether it's due to her alignment or her past. This adds an element of tension and intrigue, especially when combined with the 'lemon' elements which can heighten the emotional stakes.
A common theme is redemption. Some fanfictions explore the idea that Cinder might seek redemption before her death, realizing the error of her ways. Another theme is justice. Since she has been a major antagonist, her death is seen as a form of justice for all the harm she has caused. For example, the characters who have lost loved ones to her actions finally get closure when she is defeated.
One common theme is loyalty. Fanfictions often explore how loyal Mercury is to Cinder and vice versa. Another theme is power. They are both powerful characters, and fanfictions might show their pursuit of more power or how they use their existing power in different situations.
One common theme is power. Often, fanfictions explore how Cinder and Neo gain and use their power, either together or separately. Another theme is loyalty. They are both complex characters, and fanfictions might question their loyalty to each other or to other parties. For example, in some stories, Neo might be loyal to Cinder only as long as it benefits her.
Power is a common theme. Cinder is often depicted as either seeking more power or dealing with the consequences of her power - hungry actions. Another theme is redemption. Some fanfictions explore if she can be redeemed after all the bad things she's done.