Dark Perachel where after ToA Percy started his own rebellion and Apollo realized too late that his oracle is no longer his.
Well, it's not exactly what you asked for, because it's Rachel, who starts the whole thing, but- here you are ;)
Apollo was content. He was finally back to where he belonged - on the Olympus, being worshiped and adored. It wasn't just the power he missed - although that was a considerable boon - or the almost obscene way he was spoiled by his subjects. No. It was the knowledge that his status as the God of Sun, Truth and Prophecies meant that after fulfilling his (injust) punishment, he was, once again, one of the most regarded gods, and anything he said or done was considered automatically as it was for the betterment of the gods. After all, the God of Truth was always expected to be truthful…
But they didn't realize that "truth" was subjective.
So, when he suggested this and that, even his paranoid father, Zeus, was sure and certain that his ideas were the right way to step on.
The fact that each and every suggestion of his had somehow made his life better, expanded his realm a bit more, and given him a bit more power went unremarked. Nobody noticed it, not even the hawk-eyed Hermes, who knew him the most, nor the strategic prodigy Athena.
When he first considered merging with the Oracle - just to make sure the gods gained deeper understanding of their future, not because it would give him more power, of course -, he didn't really think about the consequences. What would happen with the current vessel, or how the demigods would get their prophecies before the quests. But he didn't need to consider them; Zeus loved the idea.
Rachel Elizabeth Dare was a wonderful Oracle. Too bad she couldn't see her end. It was a shame her own self was too merged with the Oracle that they were basically one being. If only she would have been less perfect for the role, maybe he could have torn the Oracle of Delphi out of her soul without hurting her much, but… sacrifices were needed to be made.
She was still alive when he reached her, twitching and shuddering on the floor of her cave as he pulled on the Oracle's soul.
"You will regret this," she rasped, but Apollo just smiled. It was just an empty threat of a dying mortal, nothing to be worried about. Nobody would ever know what happened. And, it wasn't like the demigods would do something about it. Not even Percy Jackson was idiotic enough to attack the gods.
"I doubt it, sweetie," he crooned, and pulled.
He stayed there, listening to her ragged breaths until they stopped coming and he could feel his power increasing.
He felt full, brimming with unrestrained power. He didn't realize that that wisp was more than just prophetic power.
It was a heady feeling, and he wanted more.
When he returned home, to his island, not to the Olympus, he felt… off. He was breathing heavily as grey and black dots were dancing in front of his eyes. It seemed, even the God of Healing could get sick.
Poor Apollo. Must have been something he ingested…
"I told you you were going to regret it," a formless, hauntingly familiar voice singsonged quietly, as he blacked out.
-*-*-
It was the first time after working that he wished he didn't have golden decoration in his room. The shining light hurt his eyes, he had to cover them with his hands, but the splitting headache stubbornly remained.
"Rise and shine, Chicken," the voice laughed cruelly. Any hope that last night has been a hallucination vanished, she was still there. She had embedded herself into him, not merged, but clawed a part for herself in his mind, in his essence. She was part of him, and not in the way he intended.
"It can't be happening," he denied, staring into the mirror. His left eye was his own serene blue one, but the right… it was green, glinting poisonously.
"Hi, there, roomie!" She snarked. His face was his, it never moved, but he could almost see her saying it. Somehow, someway, Rachel Elizabeth Dare became a part of him.
He did the only thing he could think of: pretend it wasn't happening. Pretend that she wasn't commenting on whatever was happening in the council, pretend he wasn't itching to grab a paintbrush, pretend he wasn't craving for coffee - mocha, with lots of chocolate and whipped cream, and not his own light roast espresso.
Pretend his own horses didn't behave like he was a stranger.
She left him alone during the journey in his chariot, and he could finally breathe again,fringe in control over his body and his thoughts. He could almost fool himself that it was over, that her power was only able to grant her a last wish, but the invading presence of the Oracle was still there. Watching. Waiting.
Driving over Camp Half-Blood wasn't in his plans, but he must have instinctively gone that way, as he was driving that way for the last few days in order to look for the best opportunity to get the Oracle. The usually busy camp was now quiet, bordering on deserted.
"I wonder why…" she commented, as if she knew something he didn't.
"It's dinner time. They are all eating," he replied, grinding his teeth. "There's nothing to worry about. If there would be, I would know about it," he huffed, perfectly secure in it. He was the God of Prophecies, he had the Oracle of Delphi in him - there was no way something was happening without his knowledge. Rachel Elizabeth Dare's presence was just an accident, nothing more.
"Hmm…" she hummed.
"Shut up! I don't have to listen to you! You are nothing, but the memory of an idiotic little chit. As soon as I merge fully with the Oracle, you will be gone," he shouted, thankful he was alone in his chariot, and nobody could hear him talking to himself.
"Huh, really? Say… how do you like your coffee?" She asked, voice light and suspiciously even.
He looked down at his cup. It was a Starbucks mocha latte with extra whipped cream and chocolate syrup on top.
He didn't remember ordering it.
-*-*-
He hated to admit it, but part of him loved to just take a back seat and let her handle things. She was good with people, both empathic and efficient at dealing with their tiny, irrelevant issues. It was his idea, of course, to let her deal with the things he hated to do. It wasn't because sometimes he found himself blacked out, not remembering how he got from one place to another.
It was what he wanted.
He gave her the leading position - she didn't take it.
Day by day, week by week, the blackouts turned worse. One moment he was giving a concert to the Muses, the next he found himself blinking awake, claw marks and love bites peppering his body. There was no indication of who he - she - fucked, whoever they were, they were always gone before he returned. Only her smugness remained.
And her.
She wasn't disappearing, she wasn't weakening. On the contrary, the place she occupied within him grew bigger and bigger as the days went by, and he could do nothing about it.
He could have handled her presence, but not this - this feeling of powerlessness. He gained nothing by consuming the Oracle, losing, on the other hand, he lost a lot.
It terrified him. But his waking moments, where he could have tried to fight against her, were far and far between.
"Don't worry, Chicken… It all ends, soon," she whispered, winking in the mirror.
As she brushed his hair, he noticed that as the light shone on his golden locks, they had a slight red tint to them. The gold was slowly, but surely turning into copper.
-*-*-
Still, nothing seemed out of the ordinary, until one day, when he woke up earlier than usual. Or later - seeing that the darkness outside was closer to sunset than to sunrise.
There was a lump beside him, a body, muscled and naked, probably male.
"Oops, you are awake," noted the irritating voice, but for once, it was coming from his mouth. "It doesn't matter, not anymore," she smirked.
"Rach?" Their bed partner asked, voice hoarse and sleepy, but Apollo still recognized it. It was Perseus Jackson.
"Don't worry, sweetie. It's still me," she said, using his voice cords.
"What? No!" Apollo shouted, but no sound left their mouth. "It can't be happening," he denied.
"Don't worry, it won't take too long," she said indulgently, letting Apollo rage inside of her.
"I can't decide if you are talking to me or him, but I hope we don't have to do this for much longer. I can't wait until you take fully over so I can stay by your side for ever," Percy said, pressing a kiss on her naked shoulder.
"I was talking to you both. Soon, we will rule the world," she breathed, claiming Percy's mouth. She missed her old body, but she had to admit this body had some advantages. Still, it was a good thing that they were changing…
Percy brushed a copper curl out of her face, cheeks softer, more feminine than before. He peppered her face with light pecks, like he used to do with her freckles, and she suspected they started to show on this body too.
"That we will," Percy agreed, and Apollo could do nothing, but watch things happening from the backseat. He should have noticed before, but he didn't, and now, he payed the price.
He was slipping further and further into her skin, until he was nothing, but a forgotten passenger, while she was moving freely in the world, shaping it, changing it to her bidding, using what power he used to have over the other gods, leading them into their demise.
I know this wasn’t Riordan intention. But I’m headcanoning Dark!Apollo right now. And I think “Gaia’s influence” is a cover up. Light!Apollo (talking here) doesn’t know why he wanted to work with Octavian. Or he does and is lying.
He also admits that he wants to be the most important god to the legion. He also never says he cannot speak with Octavian which is fun. For this headcanon, whenever he wishes to appear before Octavian - he takes on the form of Dark!Apollo because that’s the form Octavian knows and expects (much like how the Greeks get the Greek version of their gods, while the Roman gets the Roman one).
Not picture, but on the next page, I think Dark!Apollo takes over a little because then Apollo suggests killing Leo over Octavian. To solve the issue. The only reason why he doesn’t is because Artemis argues against it. So he’s very much neutral, even in his Light! form.
Which is why it seemed to strange to me that in Trials of Apollo, Apollo is so against Octavian even in his own head. Like, right up to this point, Apollo isn’t really unsupportive of Octavian. So the only reason why he would be after his fall is because he cannot take responsibility (very Apollo) and decides to blame others. But even then, that’s not well comminicated in the text from what I recall.
So instead, my idea is that only Light!Apollo gets made mortal. His Dark! form being erased through this method.
“Apollo you have to stop this! You know it isn’t right.” Artemis glared at her brother with the passion of a hurricane, her voice stern and ice cold.
“I stopped doing the right thing long ago.” His voice was quiet and faraway with an edge of melancholy as if he was truly troubled by his actions.
He almost seemed remorseful. Almost.
Artemis knew not to let Apollo deceive her with a simple sound of voice. She knew all too well how he could manipulate his words to make them ring with truth despite being nothing but filthy lies. He was a powerful god and knew just the right way to wield his abilities.
“Apollo this isn’t you. The plagues are killing the mortals by the millions. Soon there will be no one to worship and remember us. No one to keep us alive.” Her underlying threat was as sharp as celestial bronze, knowing where to cut to draw the most blood.
Her auburn hair fell over her left eye, shielding Apollo from most of her view. She pushed the lock of hair behind her ear in one elegant move.
“Let the world feel my pain. The gods do not deserve to live.” Each word was coated in a thick layer of paralyzing poison.
His eyes shone with cunning and intelligence. They flamed with the desire to destroy and bring terror. They glowed merciless like the beating sun in a dry, dry desert. Apollo was to be feared.
Artemis longed for her brother. Her brother that made ridiculous haikus, helped demigods with quests, and had a hilariously high ego. The Apollo that cared for this world and the next; the one that brought life and beauty with each loving ray of honey colored sunshine.
“Apollo, please.” Her words were strangled.
Artemis tried so hard not to cry, to not show her twin the weakness he has brought on her. He would not miss the signs of her vulnerability when she let the few tears trickle down her cheeks onto the tiled floor.
“No, Artemis.” She was disappointed to see he could look right in her eyes and say this. He turned himself into a monster.
Artemis nodded solemnly in response. She knew her defeat before she even stepped foot into his palace. It was hope that brought her here, but that was vanquished like an old piece of trash.
“Wh-What are you planning to do next?” She choked out the words in a whisper with the fear of his response.
What kind of cruel twisted games would Apollo play on the mortal world?
“Well as the song goes-” Apollo peeled back his dangerously red lips in a wolfish smile and stared deviously at his sister “- Here come’s the sun.”
