In this fanfiction, some of the demigods who have fully given in to Kronos' will could be antagonists. They might see Percy as a threat because he still has some sense of his own will. For example, a son of Ares who has been corrupted by Kronos' power. He could constantly challenge Percy and try to prove his loyalty to Kronos by getting rid of Percy.
The other Titans could be main antagonists. For example, Hyperion who is known for his great strength and his desire for destruction. He might not fully trust Percy and constantly try to undermine him in Kronos' eyes. Another could be Atlas, who is already a major foe in the Percy Jackson series. He might see Percy as a threat to his own plans within Kronos' regime.
Definitely some of the more powerful monsters that are allied with Kronos. The Minotaur, for instance, could be a recurring antagonist. It has a long - standing hatred for Percy and would love to see him fail. Also, the dracaenae could be a nuisance for Percy. They are sly and could be used by Kronos to keep an eye on Percy and make sure he is following orders.
The best chapter pointer here is Chapter 249, "Maxing Out Wilderness Survival Skills!". It opens with Jiang Yan's body subconsciously shivered twice. and closes on He deserves it!] [It was absolutely the right decision for Jiang Li to....
Look to Chapter 271 for the clearest answer. It begins with He had barely finished speaking when he received a withering look from..., keeps building through How did he blurt that out?!, and lands on Gathering her thoughts, Jiang Li looked toward Jiang Yan, who was still....
Chapter 254 is the strongest chapter-level answer because it starts from Just when everyone thought that Jiang Yan wouldn't last long and would... and follows through on A Jiang Li whose head was only filled with books and who never joked or....
Look to Chapter 267 for the clearest answer. It begins with Jiang Li had just turned around when she was suddenly embraced by a..., keeps building through Before she could catch her breath, her shoulder was gripped., and lands on —However, he was indeed about to experience some misfortune..
The best chapter pointer here is Chapter 271, "How Did Shen Lan Marry an Old Fool?!". It opens with He had barely finished speaking when he received a withering look from... and closes on Gathering her thoughts, Jiang Li looked toward Jiang Yan, who was still....
Look to Chapter 270 for the clearest answer. It begins with After liking the post, Jiang Mingyu put his phone away and turned back to..., keeps building through The Ethiopian police had already investigated the attempted murder case..., and lands on A moment later, he stood up, his expression.
Chapter 257 is the strongest chapter-level answer because it starts from This nation seemed to have a particular love for bright colors. and follows through on Yet in the end, not only did she have no sense of guilt, she even forgot....
Chapter 269 is the strongest chapter-level answer because it starts from The next morning, Shen Lan's personal account posted a Weibo. and follows through on At that time, people guessed it was Shen Lan, and there were even photos....
If you want the clearest chapter reference, go to Chapter 233. Early on, [What the hell, what's this about life span ending??; later, the chapter leans on Could it be.....] [Ahhhhhh help, bullet screen shield me, it's broad....
The best chapter pointer here is Chapter 247, "Madam, Your 2000 Kilograms of Sweet Potatoes, Please Check and Accept". It opens with Facts have proved that arch-enemies often understand each other the best. and closes on Why should he expect food without contributing?] [Support!.