The Underworld could also be a setting. He might be training there to face the dark forces. The dangerous environment full of monsters and traps would provide him with ample challenges to improve his combat and survival skills.
Well, in a 'percy trains himself fanfiction', he could be training for a big battle. Maybe he's practicing his combat skills with his sword, working on his speed and agility in a secret forest glade. He might also be training his mind, learning new spells or strategies to outwit his enemies.
It could be that Percy's sense of honor led him to sacrifice himself for Zoe. If he had made a promise to protect her, he would uphold it no matter what. Also, Zoe might have been the key to solving a major mystery or threat. Percy, realizing this, chose to sacrifice himself so that Zoe could continue and complete whatever task was necessary. Additionally, his love for his friends and the greater community of demigods might have made him believe that Zoe's survival was more important than his own.
One possible motive could be extreme depression. If Percy has been through a lot of hardships in the story, like being ostracized or constantly failing in his goals, it could lead him to this drastic step.
One possible reason could be extreme despair. Maybe he faced some overwhelming challenges or betrayals that made him feel there was no way out. For example, if he lost all his friends and felt completely alone in the world of the fanfic.
One possible reason could be extreme despair. Maybe in the fanfiction's universe, Percy has faced a series of unbeatable challenges like losing all his loved ones and feeling completely alone. Another reason might be a sense of guilt. If he made a huge mistake that led to disastrous consequences for others, he could be so consumed by guilt that he sees no other way out. Also, if he was betrayed by those he trusted deeply, it could shatter his world view and push him to such a tragic end.
Well, perhaps Percy could be learning some new and powerful combat skills from Chaos. Maybe Chaos teaches him to manipulate chaos energy in unique ways for battle.
One possible plot could be Percy learning unique survival skills while training in Alaska. Maybe he has to deal with extreme cold, wild animals like bears or wolves. He could also meet local Alaskan characters who teach him their traditional ways of living and hunting, which in turn enhance his own training.
Perhaps the fanfiction could be about Naruto training Percy in stealth. Percy, being a demigod, often charges into battle head - on. Naruto, on the other hand, is a master of stealth. He could teach Percy how to move quietly and undetected. This would be a great advantage for Percy when he has to infiltrate a monster's lair or spy on the enemy. The story could show Percy struggling at first but gradually getting better with Naruto's guidance.
It could be that Hera is a powerful spirit or goddess in the Naruto universe who has been awakened. She sees potential in Naruto and decides to train him to reach his full potential. The plot might include Naruto facing challenges within himself as he tries to master the new skills Hera teaches him. There could also be a sub - plot where other ninja clans become suspicious of Naruto's new powers and training, leading to some conflict.
One scenario could be that they are facing a powerful monster. The monster is about to strike Annabeth, and Percy jumps in front of her at the last moment, taking the fatal blow. Another possibility is that they are in a dangerous situation like a collapsing building or a sinking ship, and Percy uses his powers to ensure Annabeth's escape while he stays behind and perishes.