Survival is a big one. Characters in the novel often have to figure out how to get food, water, and shelter on the lost island. Another theme could be isolation. Being cut off from the rest of the world can have a huge impact on the characters' mental states.
The theme of adaptation is crucial. Characters need to adapt to the new environment of the lost island. This includes adapting to different climates, terrains, and available resources. Additionally, the theme of self - reliance is often explored. With no one else to depend on, the characters have to rely on their own skills and knowledge to survive on the island.
Power dynamics. These novels often show how imperial powers exerted control over colonies, like the way they used military force and political manipulation.
Power is often a main theme. Impeachment involves the power dynamics between different branches of government. It shows how power can be challenged and held accountable.
If we assume such a novel exists, it might explore themes like power dynamics. In a sex contract situation, there could be an unequal distribution of power between the parties involved. One might have more control or influence due to the terms of the contract.
Themes of love and relationships are surely present. The grandma's romantic relationships, whether past or present, would be an important part of the story. It could show how she found love in a society that might not have been fully accepting at times. There may also be themes of resilience, as she had to face potential discrimination or misunderstanding, and yet still managed to live her life. And of course, the theme of identity in general, not just sexual identity, but also how being a grandma and a lesbian shapes her overall sense of self.
Identity is a big one. The character who is intersex and a 'golden boy' might struggle with their sense of self, trying to figure out where they fit in society, in terms of gender and also in terms of their special status as a 'golden boy'.
One of the main themes is the exploitation of the vulnerable. In these graphic novels, you often see how traffickers target those who are poor, marginalized or in desperate situations. For example, young girls from impoverished families might be lured with false promises of a better life.
I'm not sure as I haven't read this particular light novel. But generally, from the title, it might explore themes of love and betrayal. 'Netorare' often implies a situation where one's partner is being taken away, so it could be about the emotional turmoil that comes with such a situation in the context of a romantic relationship.
One possible theme could be the clash of different power systems. Naruto has his chakra - based powers and Hela has her Asgardian might. Their interactions in a fanfiction might explore how these powers interact. However, since this is a rather unique crossover, it's hard to say exactly what the main themes would be without actually reading a lot of such fanfics.
One main theme is redemption. Nagato has done a lot of bad things in the Naruto series, and in fanfics, often Naruto is the catalyst for his redemption. For example, Naruto's talk - no - jutsu can make Nagato see the error of his ways.
Acceptance is a major theme. These stories often show the journey of a young gay boy or a family with a gay child towards being accepted by society or within their own community.