One common theme is the 'forbidden love' aspect. Since Jadeite is often an antagonist in the Sailor Moon universe and Usagi is the protagonist, their relationship goes against the natural order, which makes for an interesting and often angsty story. Another theme could be 'redemption'. Jadeite might be shown as trying to redeem himself through his relationship with Usagi.
You can try fanfiction websites like Archive of Our Own (AO3). There are often a wide variety of fanfictions about different pairings, including Jadeite x Usagi. Just search for the pairing on the site, and you'll likely find a good selection. Another option could be FanFiction.net, although the content quality may vary more.
Some fanfiction communities might have threads dedicated to this pairing and lemon fanfics. You could join those communities and ask for recommendations. People there are often very helpful and can point you to some great misaki x usagi lemon fanfictions.
Lemon fanfiction often involves a certain level of romantic or spicy elements. In misaki x usagi lemon fanfiction, it might explore their relationship in a more intense and passionate way. Maybe it shows their deep emotional connection and physical attraction, with detailed descriptions of their interactions.
There's also 'When Ranma Met Usagi'. This one focuses a lot on the cultural differences between their two worlds. It shows how they overcome those differences and gradually fall in love. The descriptions of the settings, whether it's Ranma's martial arts world or Usagi's magical girl realm, are very vivid and immersive.
Tuxedo Mask could also be in the harem. He has a long - standing relationship with Usagi, and in a harem scenario, his feelings for her could be even more intense, competing with others for her love.
One common theme is friendship. Rei and Usagi have a strong friendship in the original series, and fanfictions often expand on that. They might go through challenges together and come out stronger.
Another theme is cultural exchange. Goku is from a more action - oriented, martial - arts - based culture in Dragon Ball, while Usagi is from a magical girl anime with a different set of values. Fanfictions may play with how they introduce their respective cultures to each other.
Yes, there are quite a few. You can start by looking on popular fanfiction websites like Archive of Our Own. There you might find various interpretations of the Usagi x Rubeus relationship, some focusing on their potential romantic development, while others might explore a more complex friendship dynamic.
One of the typical themes is the contrast between their personalities. Haruka is often seen as more cool and aloof while Usagi is bubbly. Fanfictions play with how these different personalities interact. Also, the theme of protecting each other is quite common, especially in stories where they face threats together.