Another theme is adventure. Since they are in a virtual world, they often go on quests together. Fanfics will describe their adventures, like exploring new areas, fighting powerful enemies, and solving mysteries along the way.
The theme of self - discovery also appears frequently. Both kirito and eugeo are on a journey to understand themselves better. In the fanfics, their relationship with each other can play a big part in this self - discovery. For instance, through their interactions, they might learn about their own strengths and weaknesses.
Adventure is also a popular theme. Since they are in a virtual world in Sword Art Online, fanfics may take them on new and exciting adventures that were not in the original plot.
Friendship is a common theme. Their bond as comrades in the virtual world is often explored, like how they trust and depend on each other in battles.
One common theme is adventure. Since they are from the Sword Art Online world, many fanfics involve them going on quests together, facing dangerous monsters and exploring new areas.
One more to mention is 'The Path of Two'. In this fanfic, the author explores the journey of kirito and eugeo together. It shows their growth as individuals and as a duo. It has a great plot that keeps you hooked from start to finish.
One possible theme could be friendship. As they interact in the fanfic, their relationship might grow into a strong bond of friendship.
One great 'sao kirito x eugeo fanfic' is 'The Bond Beyond the Swords'. It delves deep into their friendship and how it evolves in different virtual worlds. The story has really interesting character development and some exciting battle scenes.
Love and friendship are common themes. Many fanfics explore how their friendship could potentially turn into a deeper romantic relationship, like in 'Kirito and Lizbeth: The Unspoken Love'.
The theme of self - discovery also pops up. As they interact with each other in the fanfics, they often discover new things about themselves, like hidden strengths or weaknesses, which in turn affects their relationship.
The theme of growth, both for Kirito and the girls in the harem, is often seen. Kirito may grow as a person in terms of his ability to handle multiple relationships, and the girls may grow in their confidence and abilities as they are part of Kirito's life. Also, the concept of loyalty within the harem is a common theme, with the girls showing loyalty to Kirito and also to each other in some cases.
Another place to look is FanFiction.net. It has a wide range of fanfictions including those about Eugeo and Kirito. However, the quality can vary, so you might need to sift through a bit. Check the reviews and ratings to find the better ones.