Author's Note: A possible start for a "Godlike!Harry". Brief X-Men crossover, but none after this intro.
As the basilisk venom burned through his veins, Harry's eyes fell closed, and darkness took him.
And then his vision exploded in light.
Stunned, he shielded his eyes against it, but the gesture did nothing to ward off the brilliance; after a moment, it dimmed, and he could see again. Well, what there was to see.
An infinite white expanse surrounded him, with no features to be seen. He looked down, but there wasn't any ground either. Perhaps he was only standing on something solid because he thought he was.
"Am I... dead?" he wondered aloud.
The he yelled and stepped back as an enormous flame appeared before him. Despite its intensity, though, he felt no heat; after a moment, it formed the shape of an immense bird, then coalesced into a woman.
He stared in awe as she stepped toward him. She looked like a Greek goddess, with her tall, athletic body, sculpted features, and cascading mane of red curls; a bodysuit in Gryffindor colors clung to her form, the golden bird emblazoned on her chest seeming to shine with an inner light. A smile curved her lips as she looked down upon him, that single gaze conveying more pride and affection than he'd ever experienced in his life.
But her face was the most stunning thing about her, for it had previously smiled at him only from Hagrid's photo album.
"M-Mum?" he asked, his voice shaking as he took a step toward her.
"Not precisely," she said, and his heart plummeted. "But you are my son, in a way."
"What? I - I'm sorry. I don't understand."
"There are many worlds, Harry," she said, placing a golden-gloved hand on his shoulder. "Some of them have no magic at all. Some of them have magic unlike anything you've ever seen. Some of them have technology so advanced it might as well be magic. Your mother was my counterpart in your world... though she never unlocked my power." An edge of cruelty came into her smile.
Her smile grew, and the light all around him dimmed until they stood in darkness. "Hear me, child. No longer am I the woman you knew," she intoned, and a great flame expanded out from her body, engulfing him and her both. "I am fire. And life incarnate." The words were no longer just speech; they seemed to reverberate through his very soul. "Now and forever - I am PHOENIX!"
He cried out as the whole world exploded into flame. The heat overwhelmed him, and yet he did not burn; the light scorched his eyes, and yet he could still see. After what seemed like an eternity, he found himself becoming able to bear the all-encompassing sensation - indeed, some part of him told him he could no longer live without it.
"What is this?" he breathed, looking all around him at the inferno that was like the heart of a star. She chuckled.
"This is my power," she told him. "As best you can comprehend it." She chuckled again. "The immortality and apotheosis of which your world's countless Dark Lords have dared to dream - I attained it." Spreading her arms wide, she pronounced, "And far more."
The flame faded, and they stood as giants against a landscape of utter darkness studded with countless stars. With one dainty hand, she reached out and plucked a star from the firmament, then raised it to her lips and bit into it. Like a berry squirting out its juices, it flared briefly, and was gone. "Would you care to have one, my dear boy?" she asked, taking another one and offering it to him.
He craved the loving indulgence in her words more than all the stars in the sky. "Er - no thanks," he said, staring at it. He could see a few little dark spots on it, and arcs and bursts on its surface; it looked just like the pictures he'd seen in his Muggle textbooks, before he'd gone off to the Wizarding world. "If-" Words briefly forsook him, but he managed, "If - um - that's a real star, I think it might be a little hot for me."
She laughed, but there was no meanness in it. "Oh, child." She put the star back and tousled his hair. "You are still so young."
For a moment, he wanted to insist to her that he was nearly thirteen, but having a mum - or an alternate version of his mum - to coo over his youth was such a novel experience that he didn't dare disrupt it. "Was... was that a real star?" he asked, staring at the starscape around them. He could maybe just barely see planets - if he really squinted.
"I am no mean provincial god," she said with a smirk. "The universe is vast, child. When I speak of apotheosis, I do not refer to becoming a chieftain of some meager speck of dust, thinking myself great only because I lack the vision to see the vaster realm beyond." She raised an eyebrow. "On that note, would you like to be rid of the need for your glasses?"
He gawped at her. At some level, he'd taken the scene around him as all some great metaphor; it had not occurred to him that a self-professed goddess could - actually do anything for him. "Yes - yes, please!" he said eagerly.
A moment later, his vision blurred oddly, and he realized in another instant that it was because he still had his glasses on. When he removed them, he found his sight sharper than it ever had been. "My G- Thank you!" he blurted out. "Thank you so much!"
She laughed. "It's the least of what I can do for you, my dear boy." Leaning down, she conspiratorially whispered in his ear, "Would you like me to fix your world for you?"
"I - um - I'm so sorry," he said in confusion. "I don't understand."
"I could kill all your enemies for you in an instant," she said, in the same tone Hermione might use in offering to fetch him another quill if his snapped. "Give you power beyond your wildest dreams. Open the way to the stars for you, if such a little thing should entertain you. Construct a nation - or a planet - entirely populated with beings that worshiped you. Anything you like, child. I am not a kind goddess - but I am fond of my children, from whatever world they may be."
His mind briefly stopped working. Anything? This - this had to be a joke. He -
He opened his mouth, then shut it and was thoughtful. The image of a bloated blond bully crossed his mind. "I - I don't know," he said at last. "I - I've seen what getting anything you ever want, all the time, does to a person. I'd - prefer to fight my own battles, I think."
She smiled at him as though he'd passed some sort of test, and his heart leapt. "That is just the response I would expect from a child of mine."
Then her hand touched his forehead, as though in benediction. He looked up at her curiously. "However - forgive an indulgent mother." Always, he wanted to say, but his throat closed up and wouldn't let him speak. "For the trials you will face, I think you'd benefit from... a little gift. The merest fragment of my power."
Warmth, such as he'd never felt, filled his body, surging through his veins and encompassing his very core. Then came a burst of dazzling radiance, but this time, he realized, it came from within. "Farewell, Harry," she said as all things faded from view. "I daresay you're far more prepared to fight your battles now, my child."
"Wait!" he shouted as the light swallowed everything. "Will I see you again?"
"Oh," came the faintest of whispers, "achieve your full potential, and I believe..."
Yes, a final feeling breathed across his skin, and he opened his eyes.
He was back in the physical world again. Fawkes was nowhere to be seen, but now the entire Chamber was illuminated in red and gold, as though by some great flame. Standing, he happened to realize that flame was him, and he smiled.
Tom Riddle's shade stared at him in mortal terror.
"Hear me, Riddle," he intoned, striding forward. "No longer am I the boy you knew..."
Author's Note: So yeah - now and forever, Harry is (this dimension's) Phoenix. Or incarnation of the Phoenix Force, if you prefer the mass of bizarre retcons that go back and forth on whether Jean Grey is Phoenix, an avatar of the Phoenix Force, the avatar of the Phoenix Force, etc. My intent here, however, is that the Phoenix speaking to Harry here is a version of Jean Grey who was Phoenix, and then Dark Phoenix... and - to quote Uatu the Watcher - "when faced with a choice between keeping her god-like power - knowing she would then wreak death and destruction upon the stars - and dying herself"... chose the former. Asking what became of her universe of origin... is ill-advised.