One possible theme could be the relationship between humans and deathclaws. It could be about how humans learn to co - exist with these fearsome creatures, or how they communicate in a non - violent way. Another theme might be the mystery surrounding deathclaws, like their origin or their unique abilities.
If we rule out the adult - related aspects, common themes in deathclaw fanfics could involve exploration of the deathclaw's ecosystem. For example, how they fit into the post - apocalyptic food chain. Also, the stories could focus on the moral dilemma of whether to kill or protect deathclaws, given their often - portrayed as menacing nature in the game lore.
Well, ignoring the inappropriate 'lemon' aspect, in dragon harem fanfics, cultural clashes can be a common theme. If the dragon harem consists of characters from different races or cultures, there will be clashes and also reconciliations. Also, self - discovery is often a theme. Each member of the harem may go through a journey of self - discovery as they interact with the dragon and other harem members. For example, a human in the harem might discover new magical abilities or a new understanding of their place in the world.
Common themes could be friendship between Ryoshi and Ryuko. Maybe they go on adventures together, facing challenges and growing closer as friends. Another theme could be about them achieving a common goal, like saving their world or something important to them.
Since we should avoid lemon fanfictions which are often inappropriate, let's consider regular Rhaegar and Lyanna fanfictions. A common theme is the forbidden love aspect. Their relationship was against the norms of their society, with Rhaegar being a Targaryen prince and Lyanna a Stark girl. Another theme is the impact on the political situation. Their union led to a series of events that changed the power dynamics in Westeros.
Another theme could be the survival aspect. Ripley is known for her survival skills against the Xenomorphs. In non - adult fanfic, this could be emphasized more. She might use her wits and knowledge to outsmart the Xenomorphs. Maybe she discovers a new weakness of the Xenomorphs through her experiences. Also, the idea of the Xenomorphs as a force of nature that Ripley has to deal with is a recurring theme.
In non - adult 'rin and shiemi fanfics', a frequent theme could be their cultural differences within the story world. Rin is a bit of an outcast because of his heritage, and Shiemi comes from a different background. Fanfics might play with this, showing how they bridge those gaps. Additionally, the theme of self - discovery could be there. As they interact, they might learn more about themselves and their own potential, which in turn affects their relationship.
One common theme could be the reaction of the other characters in the Naruto universe. How Naruto himself might respond, or how their friends deal with the situation. Another theme could be the exploration of trust and loyalty in relationships, not just romantic ones but also friendships. Also, it might touch on the idea of redemption for Gaara if he realizes his mistake.
One common theme could be the exploration of different monster species' cultures. Even within the context of a harem and with the 'lemon' elements, there might be an underlying exploration of how different monster characters interact based on their species' norms. Another could be the power dynamics, as some monsters in Monster Musume have different levels of power or abilities, and this could play into the relationships in the fanfic.
It could potentially explore themes of betrayal and its consequences not just on the relationship but also on the characters' self - esteem and their place in the fictional society. Maybe it also delves into themes of forgiveness or the lack thereof.
It could be about the relationships between the characters in new and interesting ways. Maybe exploring the family dynamics in a more comical or heartwarming context that isn't in the original show as much.
Another common theme could be the lizardman's struggle for acceptance in a world dominated by other races. This could involve them trying to prove their worth, intelligence, or ability to co - exist peacefully. Their physical characteristics might also play a role, like their scaly skin or sharp claws, which could be both a source of strength and a reason for others to fear or misunderstand them.