One interesting fanfiction could be where Female Percy struggles with her identity as Kronos' daughter. She might have to battle against the dark nature she inherits while trying to uphold the values she learned from her friends at Camp Half - Blood. For example, she could be in a situation where she has to choose between following Kronos' old plans for domination or forging her own path of peace.
I'm not sure of a specific title, but in general, these types of fanfictions often explore how being Kronos' daughter would make her an outcast among the other demigods. They might also show her coming to terms with her father's actions and trying to make a name for herself separate from his dark legacy. You could search on popular fanfiction sites using relevant tags like 'fem Percy', 'Kronos' and 'daughter' to find some good reads.
Another theme is redemption. Many fanfictions explore the idea of Female Percy trying to atone for Kronos' past wrongs. She might be on a mission to prove that just because she's his daughter doesn't mean she'll follow in his footsteps. This often involves her making sacrifices and difficult moral choices.
One common theme is identity struggle. Since Kronos is a feared figure, Percy has to figure out who she is apart from being his daughter. Another theme is redemption. Some fanfics explore if Percy can redeem her father's name or if she has to atone for his actions.
The plot could involve her on a quest. Maybe she's searching for a way to break the cycle of Kronos' evil. She might team up with Percy Jackson and other characters. They could face various monsters and challenges along the way. And she could be constantly battling her own inner demons related to her father's nature, like a tendency towards power - hunger that she has to overcome.
One great 'Percy Daughter of Kronos' fanfiction is 'The Daughter's Destiny'. It explores how Percy, as the daughter of Kronos, struggles with her identity in a world that fears her father. The author does an amazing job of creating a complex character out of Percy in this new role.
She could potentially have the power of regeneration. Kronos was a powerful being, and if she inherits some of that essence, she might be able to heal from wounds faster than normal demigods. This would make her a very tough opponent in combat as she could keep coming back even after taking serious hits.
In many fanfictions, Percy might use his water powers in a unique way. Maybe he combines his control over water with his sword fighting skills. He could create a giant water vortex to disorient Kronos and then strike with Riptide while Kronos is off - balance.
Maybe there are some original characters created by the fanfiction author. These characters could have their own unique abilities and backstories. They might be the ones who tip the scales in Percy's favor, for instance, by having a special power that weakens Kronos just before Percy makes the final blow.
Luke could also be a prominent character. Since he has a complex relationship with Kronos in the original story, in fanfiction he could play a role in either helping or hindering fem Percy's efforts against Kronos. Nico di Angelo is another possibility. His powers over the dead could be useful in a fight against Kronos, and he might team up with fem Percy for that reason.