Nyx, the goddess of the night, is quite popular in fanfictions. Her dark and mysterious nature makes her an appealing character. Writers can play with her powers, such as her control over the night, dreams, and all the things that lurk in the darkness. She can be portrayed as a powerful and independent figure, or she can have complex relationships with other gods or demigods. Erebus, the god of darkness, is also a favorite. His connection to Nyx and his role in the primordial cosmos offer a lot of material for fanfiction writers. He can be a source of great evil or a misunderstood figure trying to find his place in the world of the story.
In the Percy Jackson universe, it could be Chaos. Chaos is often considered one of the most ancient and powerful entities. If Chaos were the eldest god in the fanfiction, it would bring a whole new level of power and mystery. Percy would be dealing with a being that is essentially the origin of everything, and its motives would be very difficult to understand.
A frequent theme is the resurrection or return of the eldest gods. In some fanfictions, the idea that these long - forgotten or sleeping gods awaken to find a world that has changed drastically is explored. This can lead to all kinds of conflicts and reconciliations. Also, the concept of the eldest gods' domains is a big part of it. For instance, if a fanfiction focuses on Gaea, the earth goddess, it might explore how she views the modern world's treatment of the earth. And the theme of redemption can also be found. Maybe an eldest god has made mistakes in the past and now tries to make amends in the context of the Percy Jackson universe.
Another plotline could involve the eldest god having a prophecy related to Percy. This prophecy could force Percy to make difficult choices between his loyalty to his friends and his newfound role in the eldest god's plans. For instance, he might have to sacrifice a chance to save a friend in order to fulfill a greater purpose for the world as dictated by the eldest god.
Percy Jackson himself is often very popular. Fans love to write more about his adventures, his relationships with other characters, and his growth as a demigod. He's the main character of the original series, so it's natural that he remains a central figure in fanfictions.
Percy Jackson himself is often very popular. People love to write about his further adventures at camp, or how he deals with new threats. Annabeth is also a favorite. Fanfiction writers might explore her relationship with Percy more deeply or show her using her wisdom in new and interesting ways. Another popular character is Nico di Angelo. His dark and brooding nature makes for great storytelling, especially when he interacts with the other campers at Camp Half - Blood.
Percy Jackson himself is obviously very popular. He's the main character in the original series and in many fanfictions, his growth and new adventures are central. Another popular character is Annabeth. Her intelligence and strategic thinking often play important roles in the battle - related fanfictions. Also, Ares, as the god of war, is often a key figure in these stories.
It could be a new, powerful Titan that has emerged from the depths of Tartarus. This Titan might be jealous of the eldest primordial's power and wants to either destroy it or take its power for itself. And since Percy is associated with the eldest primordial, he becomes the Titan's target as well.
He might be very wise. Having been around the longest, he would have witnessed countless events and learned from them. So, he could offer very profound advice to other characters in the fanfiction.
His mother, Sally Jackson, could play an important role as an ally. She has a strong will and has always been there for Percy. Also, Tyson, his cyclops half - brother, could be a powerful ally with his strength and loyalty. And don't forget about the Nymphs. Some of the water nymphs might help Percy since he has a connection to water.
Annabeth is also highly popular. Her intelligence and relationship with Percy add a lot of depth to the stories. In fanfiction, she can be involved in solving complex puzzles or leading her own quests.