One possible theme could be cooperation. As mentioned before, their different skills can lead to a great partnership. Another theme might be the contrast between their natures. Hephaestus' more physical and hands - on work compared to Athena's intellectual pursuits.
It could be a story full of creativity. Hephaestus, the god of blacksmithing, and Athena, the goddess of wisdom. Maybe it could show how Hephaestus creates amazing artifacts with the wisdom and inspiration provided by Athena. Their interactions might involve Hephaestus seeking Athena's advice on his works, and Athena being impressed by Hephaestus' craftsmanship.
Fanfiction.net might also have some 'aphrodite x hephaestus fanfic'. You can browse through different categories and use the search function. However, keep in mind that the quality can vary widely. Look for stories with high ratings and positive reviews. Some authors might also have their own blogs or websites where they post their fanfics, so it could be worth doing a general internet search for those as well.
In a 'aphrodite x hephaestus fanfic', one could expect to see a lot of emotional drama. Since Aphrodite was often associated with affairs and Hephaestus was her husband in some myths, the fic could delve into their marital issues. It might show how Hephaestus deals with Aphrodite's unfaithfulness or how Aphrodite feels trapped in a marriage with someone she doesn't fully love. The fic could also explore the idea of redemption and forgiveness in their relationship.
In Greek mythology, Athena and Hephaestus don't have a typical 'love story' in the romantic sense. Hephaestus once tried to assault Athena. But Athena, being a virgin goddess, resisted him. This event led to Hephaestus spilling his semen on the ground, which gave birth to Erichthonius in a rather strange way.
The key event was Hephaestus' unwanted advance towards Athena. As a virgin goddess, Athena didn't tolerate it. This led to the strange birth of Erichthonius.
One common theme is the exploration of their different natures. Hephaestus, being the god of fire and forge, and Athena, the goddess of wisdom. Their relationship in fanfiction often delves into how these two different aspects interact. For example, how Hephaestus' practical skills might complement Athena's intellectual abilities.
Another theme could be the idea of acceptance. Percy, being a demigod, might face some challenges in being accepted by Hephaestus, who is a god. And Hephaestus, with his own insecurities, might also struggle to accept Percy in some fanfics. This creates a lot of emotional depth in the stories.
Since 'lemon fanfic' implies sexual or improper content, it's not something that should be associated with the relationship between Annabeth and Athena. The proper characteristics of their relationship in fan - fictions should be about things like Annabeth's respect for Athena, her following of Athena's wisdom, and how Athena might guide Annabeth in her adventures.
One common theme is the clash and then the eventual understanding between two very different cultures. Naruto's world of ninjas and Athena's more mythological world. Another could be the power - up theme, where Naruto might gain some abilities related to Athena or vice - versa.