In many of these fanfics, the theme of discovery is there. They discover not only each other but also themselves. Legolas might discover a new side of himself through his love for someone. Also, the theme of nature is common as Legolas has a deep connection to nature, and it often plays a role in the development of their relationship, like meeting in a special grove or by a magical stream.
Family is a common theme. Given their father - son relationship, many fanfics explore how they interact as family members, the love, respect, and sometimes the misunderstandings within the family.
A common theme is adventure. Since Legolas is often involved in various quests in Middle - earth, the fanfics usually have the reader joining him on these adventures, like exploring ancient forests or fighting against orcs. Another theme is the cultural differences. The reader, usually being a human or from a different race, has to navigate the elven culture that Legolas is a part of.
One common theme is the 'forbidden love' aspect. Since Legolas is an elf from a different world or culture in the Tolkien universe, the relationship with an OC (original character) often faces various obstacles. Another theme is the adventure - love combination. The couple might go on quests together, and their love develops during these adventures.
Friendship is a common theme. Legolas and Aragorn have a strong bond in the original story, and fanfics often expand on that. Another theme is loyalty, as they are both loyal to the fellowship and to each other.
One common theme is friendship. They form a strong bond during the events of FotR. Another theme is mutual respect. They respect each other's abilities and cultures.
One common theme is friendship. Their bond is often explored, like how they support each other in difficult situations. For example, in many fics, Aragorn might be in a tough leadership decision and Legolas offers his unique perspective. Another theme is loyalty. They are always loyal to each other and to their cause, and this is often a central aspect of the stories.
Love and romance also feature often. It could be a love story between female Legolas and an original character created by the author. Or it could be a reimagined version of a relationship that was hinted at in the original works. Her elven grace and beauty make her an interesting character for love - related plotlines in these fanfictions.
One common theme is the reaction of the other characters. They might be shocked, supportive or confused. Another theme could be the physical and emotional changes Legolas goes through.
One common theme is adventure. The OC often goes on quests or adventures with Legolas. Another is friendship, as they develop a bond that might be different from the ones Legolas has with his known companions. And love can also be a theme, whether it's a budding romantic relationship or a deep platonic love.
One common theme is the struggle for understanding. Thranduil is often portrayed as a complex character, and Legolas may have to work to truly understand his father's love. Another theme is protection. Thranduil wants to keep Legolas safe, which is a form of love. Also, the theme of legacy is present. As Legolas is to inherit from Thranduil, their love relationship is tied to the future of their people.