If Percy joins the Titans, his allies could be some of the lesser - known Titans who are tired of the constant fighting. They might see Percy as a way to bring about change. Enemies? Well, the Titans who are fully committed to overthrowing the Olympians and establishing their own tyrannical rule would be against him. Also, Poseidon, his father, might be conflicted about Percy's choice and could end up being an enemy if Percy doesn't change his course.
As for enemies, Percy could encounter the Titans who were once banished there. They might see Percy as an intruder and a threat, and try to eliminate him. Also, the monstrous creatures that lurk in Tartarus, like the Empousai or the Chimera, could be his foes.
Well, perhaps Percy could be seeking a new kind of power or a different way to prove himself. He might initially be lured in by the Titans' promises of a more 'free' and unconstrained way of using his abilities. Maybe he gets disillusioned with the Olympians and thinks the Titans offer a better alternative.
His old friends from Camp Half - Blood like Annabeth could be his allies. She would support him through the transition of becoming a god. Grover too, as his long - time friend, would be there for him. Also, some of the minor gods who have always been on good terms with Percy, like Hestia, might offer their help and guidance as he steps into his new role as a god.
Some of the more traditional and rule - following demigod groups at Camp Half - Blood could be against him. They believe in following the established ways and Percy's rogue behavior goes against that. They might see him as a troublemaker and try to bring him back to the 'right' path.
Annabeth could be a great ally. Her intelligence and strategic thinking would be very useful in dealing with the chaos Percy often gets into. She could help him plan his moves and figure out the motives of chaotic enemies.
Annabeth would definitely be a great ally. Her strategic mind could help Percy navigate the complex situations that come with his Titan heritage. She could also research about Titans and find ways to counter any threats that target Percy because of his parentage.
His friends from Camp Half - Blood would be his allies for sure. Annabeth, with her strategic mind, would be invaluable. Grover, the satyr, could help Percy communicate with nature spirits which could be useful. But also, some of the minor gods who feel left out by the major Olympians might side with Percy. For example, Hecate could use her magic to assist Percy, seeing him as a chance for a new order in the Olympian world. There's also Tyson, Percy's cyclops half - brother, who would be a strong and loyal ally.
Grover could also be an ally. His connection to nature might give Percy some unique advantages in Tartarus. Additionally, some of the less hostile creatures in Tartarus, like the friendly Cyclopes, could side with Percy. They might see him as a more just ruler compared to the chaos that usually reigns in Tartarus. Also, Chiron, with his vast knowledge and experience, could offer guidance from afar, which could be considered a form of alliance.
There could be a group of anti - military rebels outside the military. They see the military as a tool of oppression and are constantly causing trouble. Percy might have to deal with them, either through combat or trying to negotiate and understand their point of view.
One of his main allies could be an Atlantean princess. She could be well - versed in the ways of Atlantis and help Percy navigate the complex social and political structures. Another ally might be an old Atlantean sage. The sage would have a vast knowledge of Atlantean magic and history, and could offer Percy valuable advice. There could also be a merman who is an outcast like Percy in some ways. They bond over their differences and help each other out in tough situations.