The Third Hokage could also be a character to adopt Naruto. Since he has been in a position of authority over Naruto, adopting him would be a way to ensure Naruto has a proper family. He could use his influence and knowledge to guide Naruto in a more personal way, both in terms of ninja skills and understanding the politics of the village.
Iruka Sensei could be a likely candidate. He already has a close bond with Naruto and cares for him deeply. Adopting Naruto would be a natural extension of that relationship, and he could provide Naruto with a stable home life and continue to mentor him in his ninja training.
Maybe an old hermit who lives in the mountains outside Konoha adopts Naruto. The hermit could be a master of some long - forgotten ninjutsu. Under his tutelage, Naruto would learn these ancient techniques and use them to protect the land around the hermit's dwelling. He might also gain a deeper understanding of nature and chakra from the hermit.
A strong female ninja from a hidden village that was destroyed. She has a big heart and sees Naruto as a chance to start anew. She can teach Naruto her unique fighting style which is a blend of agility and powerful strikes.
The Hyuga clan could also be a possibility. Given their strong bloodline and their focus on family and tradition, they might adopt Naruto. They could teach him their Gentle Fist technique. And Naruto could use his unique energy and determination to perhaps improve or modify the technique in some way. Plus, he could help the Hyuga clan with any external threats they face due to their valuable Byakugan.
It could be the Hyuga clan. Since they are one of the most prominent clans in the Naruto universe and have a very regal and traditional way of life. They might see Naruto's strength and determination and decide to adopt him, especially if they think he can help protect their secrets and status within the ninja world.
The Weasleys are very common. Given their big hearted nature and their closeness to Harry in the original story, it makes sense for them to adopt him in fanfiction. They already treat him like family, so it's a natural fit.
It's possible that some of Percy's old enemies, like Kronos' minions who somehow survived, might resurface in this fanfiction. They could be trying to stop Percy from achieving whatever goals Chaos has for him. Also, some of the gods might get involved. They could be curious about Percy's new situation, or they might be worried that Percy's new power under Chaos could be a threat to them. And then there could be some mysterious entities from the Chaos - related realms that we haven't heard of before in the original Percy Jackson stories.
Zeus is a possibility. As the king of the gods, he might see Percy's potential and adopt him to have an ally among the demigods. Another could be Poseidon, since Percy is already his son in the original story. It would be an interesting twist to have Poseidon formally adopt Percy in a more divine way.
Obviously, the Jedi who adopt Naruto would be main characters. For example, a Jedi Master like Obi - Wan Kenobi could be the one to discover Naruto and take him under his wing. Another could be Yoda, who would be very interested in Naruto's unique abilities and would play a role in his training. There could also be other young Jedi trainees who become Naruto's friends or rivals during his time at the Jedi temple.
An elf who adopts Naruto could be a main character. This elf might be an elder with great wisdom and magical powers. They see something special in Naruto and take him under their wing. Another character could be an elven child who becomes Naruto's friend. They teach each other about their respective worlds and grow together.
Gaara could be a main character. Since Naruto has a connection with him already, Gaara could play a big role in helping Naruto adjust to life in Suna. Maybe he becomes like a brother to Naruto in this new setting.