Perhaps it's a story about them adapting to life on Olympus. Thalia could be training the young demigods there, Nico might be exploring the more mysterious parts of Olympus that are related to the Underworld, and Percy could be dealing with the politics of the place. It could be full of adventures as they face challenges from both the gods and other creatures.
Well, one possibility could be that they are given special status on Olympus. Maybe they are tasked with keeping the peace among the gods, which would lead to a lot of interesting interactions with the deities. They might also use their unique powers to improve the living conditions on Olympus, like Percy controlling water to create beautiful fountains or something.
In this fanfiction, they could be living on Olympus as a sort of reward for their great deeds. Percy, with his heroic acts, Thalia for her leadership, and Nico for his contributions to the demigod world. Their presence on Olympus could disrupt the normal order at first, but then they start to make positive changes. For example, Percy might introduce new ways of using water power for the benefit of all on Olympus, while Thalia and Nico bring in their own unique perspectives and skills.
A practical answer is Chapter 60, because it turns the idea into a concrete scene. The chapter opens with What's with Jiang Yan, treating his own sister Jiang Li like this?" "He..., adds pressure through Jiang Yan, are you that lacking in confidence?, and ends on And in traditional characters?".
Chapter 12 is the strongest chapter-level answer because it starts from Qin?" Jiang Li called out twice, and only then did Mrs. and follows through on The glass shattered on the floor with a crash, attracting the attention of....
If you want the clearest chapter reference, go to Chapter 38. Early on, Jiang Li had also observed the girl who had just entered.; later, the chapter leans on Before arriving, she had briefly reviewed the profiles of the other three....
Chapter 38 is the strongest chapter-level answer because it starts from Jiang Li had also observed the girl who had just entered. and follows through on He Yun coldly turned his head and continued to maintain his aloof persona..
The best chapter pointer here is Chapter 37, "Those in the know anticipate the transformation, while the oblivious think it's a fashion show.". It opens with The barrage was suddenly filled with hahas, but the two guests present...
The best chapter pointer here is Chapter 58, "Jiang Yan Stranded Abroad". It opens with Facing Jiang Yan's triple barrage of questions, Jiang Li's only response... and closes on By ten o'clock, Jiang Yan was still wandering outside..
Look to Chapter 71 for the clearest answer. It begins with Shu Yan curled her lips with a hint of jealousy, "When can it be my turn..., keeps building through Who in this circle didn't know that Jiang Li had a thing for the..., and lands on Now they had to work on an empty stomach..
A practical answer is Chapter 36, because it turns the idea into a concrete scene. The chapter opens with But soon, people began to question the authenticity of Jiang Li's bare..., adds pressure through Qi Tianyu, catching the signal, instantly turned to the duo upon entering..., and ends on After.
A practical answer is Chapter 16, because it turns the idea into a concrete scene. The chapter opens with Just as the words fell, Jiang Shixu swiftly cast his eyes downward., adds pressure through Smelling the pleasant jasmine scent coming from her, his tense nerves..., and ends on Jiang Shixu.
The best chapter pointer here is Chapter 90, "Are You Even a Woman?". It opens with Watching He Yun gradually take control of a tractor under professional... and closes on Jiang Li finally let go of Jiang Yan's arm..