Who could be the main antagonist in a 'Percy Jackson Champion of Styx Fanfiction'?

The Titans could still be a major threat. Even if Lady Styx is involved, the Titans might see an opportunity to use the chaos she causes to their advantage. For example, Kronos could try to ally with Lady Styx to regain his power and overthrow the Olympians once again.

A powerful sorcerer who once was a disciple of Hecate but turned to the dark side could be the main antagonist. He might be jealous of Percy being chosen as the champion and wants to steal Percy's powers for himself.

A powerful Titan who has somehow escaped Tartarus and is bent on revenge against the gods could be a great antagonist. This Titan might see Percy as a key figure in the new order of the gods and fates, and so wants to destroy him. Maybe it's someone like Atlas, who has a long - standing grudge against the Olympians and now wants to take it out on Percy as the champion of the fates.

There could be a new Titan that we haven't seen before. This Titan could be more cunning and powerful than the others. Maybe he's been in hiding all this time, waiting for the right moment to emerge and lead the Titans to victory. He could manipulate Percy's friends against him and create all sorts of problems for our hero.

It could be a powerful demigod who has been corrupted by power. This demigod wants to be the sole champion of the arena and will stop at nothing to defeat Percy.

Another antagonist could be a powerful frost giant. If Percy is involved in protecting Asgardian interests related to Thor, a frost giant could be a major foe. They are strong and have their own motives for opposing Thor and his champion. They might see Percy as an easy target at first but soon realize his strength.

It could be one of Mars' old enemies, like a powerful Titan who has a grudge against Mars and sees Percy as a threat. Maybe this Titan wants to take over Mars and Percy stands in the way.

Obviously Percy Jackson himself is a main character as it's about his dip in the Styx. His girlfriend Annabeth Chase would also likely be involved. She's always by his side in tough situations and would be there either to support him before the dip or to help him deal with any after - effects.

Well, clearly Percy Jackson is one of the main characters. He's a well - known demigod in the Percy Jackson universe. And of course, Lady Styx is another main character in this fanfiction. She has her own powers and influence in the Underworld.

A powerful mythological creature that has a grudge against the god Percy is championing for. For example, a Titan who was once defeated by that god and now sees Percy as a way to get revenge. It would be a great adversary, with its own set of powers and minions.