One possible cause could be the loss of a loved one. In many stories, this kind of trauma can lead to depression. Percy might be struggling to come to terms with the death or departure of someone close to him.
Isolation might be another cause. If Percy has been cut off from his friends or community in the fanfiction, he could feel lonely and depressed. Without the support and social interaction that he needs, his mental state could deteriorate. For example, if he has been ostracized for some reason or has had to go into hiding alone, this lack of connection could contribute to his depression.
It could also be due to a sense of failure. Maybe Percy has faced a major setback in his life, such as failing to achieve an important goal. This feeling of not being good enough can often trigger depression. In the context of the fanfiction, it might be that he couldn't protect someone he cared about or he lost a significant battle.
One possible cause could be the stress from all his past quests. He's been through so much, faced many dangerous situations, and lost some friends along the way.
In the fanfiction, Percy could start by reaching out to his friends. They might offer him support and understanding, which could be a great help in dealing with his depression.
One possible cause could be the aftermath of the war. He was on the losing side, and he might feel guilty for the things he did during the war, like helping the Death Eaters. He might be haunted by the memories of the violence and destruction he witnessed or was a part of.
It could be the weight of his responsibilities. Percy has always had a lot on his plate, saving the world multiple times. The constant pressure to be the hero might finally get to him, making him feel like he can't keep up. He might start to think that one day he'll fail and cause great harm.
It could be due to social isolation. Maybe she has been ostracized by her peers or community in the fanfiction world, which makes her feel alone and unworthy. This lack of connection can lead to deep - seated depression.
Well, in fanfiction, one reason could be the loss of his friends. Percy has been through so many battles, and if he loses someone close like Annabeth or Grover, it could send him into a deep depression. Another reason might be the burden of his prophecies. He's constantly expected to save the world, and that kind of pressure can wear a person down over time.
One way is through his inner thoughts. For example, the author could write about Percy constantly doubting himself, like thinking he's not a good enough hero. His thoughts could be filled with self - blame for the things that went wrong in his adventures, even if they weren't really his fault. Another aspect could be his withdrawal from his friends. He might start avoiding them, not answering their calls or messages, and when he is with them, he seems distant, lost in his own world of despair.
Another theme is self - doubt. Percy may question his own worth and abilities. He might think that he's a burden or that he's not as strong as everyone believes. This is often explored in the context of his depression, like in stories where he hesitates to take on tasks he used to do easily.
In a fanfic, one possible cause could be the loss of his loved ones. If he were to lose Sasuke again, this time perhaps permanently, it could send him into a deep depression. He's always been so focused on bringing Sasuke back, and if that hope is completely dashed, it would be a huge blow.
The plot could involve Percy being tricked into using a powerful, ancient artifact that he doesn't fully understand. As he tries to figure out how to control it, it backfires and causes an earthquake. He then has to find a way to stop the destruction and reverse the effects of the earthquake while also dealing with the consequences of his actions, like the panic among the mortals and the possible damage to the demigod world.