One great Kronos fanfiction could be about his backstory before he turned evil. Maybe it explores his relationship with the other Titans and what led him to start the war against the Olympians.
If Kronos were to win in a Percy Jackson fanfiction, it would be a cataclysmic event. Kronos represents the old, chaotic order. His victory would mean the collapse of the current pantheon - based system. The gods' domains would be up for grabs, leading to widespread conflict among the Titans and other powerful beings. Percy and his allies would have failed in their quest to protect the world. The very fabric of the Percy Jackson universe, with its themes of friendship, heroism, and the fight against tyranny, would be shredded. It would be a very different and much darker world than the one we see in the original series.
Well, one of Percy's accomplishments in Kronos fanfiction could be his ability to resist Kronos' influence. Kronos is a powerful and manipulative figure, but Percy, with his strong will and loyalty to his friends and the gods, stands firm. This not only protects him but also gives hope to others. Another accomplishment might be his discovery of hidden powers or knowledge that helps in the fight against Kronos. Maybe he uncovers an ancient prophecy or a new way to use his powers that turns the tide of the battle.
One way for Kronos to win in Percy Jackson fanfiction is by spreading more chaos and discord. If he could make the demigods lose faith in the gods and each other, his job would be much easier. He could also try to find a way to use the prophecies to his advantage. Maybe he could twist the words of the prophecies to make the demigods make wrong decisions. And if he could somehow break the connection between the demigods and their godly parents, the demigods would be weaker and he could overpower them.
In a fanfiction, Percy could face other demigods who are suspicious of him because of his relation to Kronos. He'd have to prove that he's not going to follow in Kronos' evil footsteps. Maybe he teams up with some unlikely allies, like a child of a minor god, to show his loyalty to the good side.
To develop the character, start with his backstory. Since he's the son of Kronos, he might have grown up in a very different environment compared to other demigods. Maybe he was hidden away by a minor god who felt sorry for him. His past experiences of being alone and shunned because of his father would shape his personality, making him a bit of a loner at first.
Annabeth is often a popular character. In fanfiction, she might play a crucial role in helping Percy deal with his complex identity as the son of Kronos. Grover could also be popular as he's Percy's loyal friend and could be there to support Percy through his struggles related to his new - found heritage.
Well, one possible consequence could be that Percy gains an immense amount of power. Kronos was a very powerful Titan, so Percy might become nearly invincible. He could also face some internal struggles as Kronos' essence might try to influence his mind and 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.
Kronos is also a popular character. His menacing presence and his complex backstory attract a lot of writers. Writers like to explore his motives for rebelling against the Olympians and what made him turn into such a villain.