Well, without more context it's hard to say precisely. 'Black Lagoon' is a well - known anime, and if this is a fanfic, the 'rock kills' part could be a really creative and perhaps dark or edgy take on the Black Lagoon universe. Maybe it's about a character using rocks as weapons to kill in a scenario that the fanfic author has devised, but that's just speculation.
I'm not entirely sure as it could be a very specific or even a made - up fan - created concept. It might be a fanfic related to 'Black Lagoon' that involves something about 'rock kills' which could potentially refer to a rock - themed or rock - music - related violent or dangerous element within the fan - written story.
You could start by looking on popular fanfic websites like Archive of Our Own (AO3) or FanFiction.net. Just search for the exact title 'black lagoon rock kills fanfic' in their search bars.
The dynamic between the other characters would change drastically. For example, Dutch, who has some sort of father - figure relationship with Rock, would be deeply affected. He might turn against Revy, or the whole crew could fall into chaos and disarray. Also, the story's themes of redemption and the struggle between good and evil would be altered. Without Rock, there would be less hope for any of the characters to find a way out of the violent underworld they are in.
One possible motive could be that Rock discovers something dangerous or unethical about the underworld operations that Revy is involved in. Maybe he threatens to expose it, and Revy, being a character who often acts on impulse and to protect her own interests, decides to kill him to keep the secret.
One common theme could be the relationship dynamics within the harem. How the different characters interact with the main character and with each other. Another theme might be adventure, as 'Black Lagoon' already has an adventurous setting, and the fanfic might build on that while incorporating the harem aspect.
One common theme could be the exploration of the dark and gritty underworld. The Black Lagoon series already has a seedy and dangerous setting, and in fanfic, this might be further explored, like the moral ambiguity of the characters. Another theme could be the complex relationships. Given the diverse and often untrusting characters in Black Lagoon, fanfic might delve deeper into how they interact, for example, the relationship between Rock and Revy which is full of tension and mutual understanding in a strange way. Also, themes of survival in a lawless world are likely, as the characters constantly face threats from various criminal elements.
A common theme is the exploration of their complex relationship. Revy is tough and Rock is more of an ordinary guy in a sense, so the fics often play with how they interact and grow closer. Another theme could be adventure, as they are in the dangerous world of 'Black Lagoon' and fanfics might send them on new and exciting escapades together.
One common theme is the contrast between Rock's civilized background and the wild, lawless world of Black Lagoon, especially when it comes to rock music. The music can act as a bridge or a source of conflict.
Their relationship can be developed through shared danger. For example, if they are in a shoot - out together, Rock could save Revy in a non - traditional way, like using his knowledge of the environment to outwit the enemy instead of using guns. This would make Revy see Rock in a new light.
One possible plotline could be that Rock and Revy are in a dangerous situation during a mission. As they face a near - death experience, in a moment of relief and pent - up emotions after surviving, they share a kiss. Then they have to deal with the consequences of this new development in their relationship while still being in the middle of the criminal underworld they operate in.
Perhaps a fanfic where Rock and Revy get stranded on an island during one of their smuggling runs gone wrong. They have to rely on each other to survive, and in the process, they start to understand each other better. Revy learns more about Rock's ideals and Rock gets a deeper insight into Revy's survival instincts.