The battle paused at Voldemort's wail. And with it, the constant spell lights went out and plunged the clearing into darkness. Incanting "Lumos" was basically instinctual for nearly everyone on the field, so the venue went from frantic, multicolored light to a quiet spectacle lit throughout by small white torches.

It was a fragile moment, ready to shatter at the faintest shove.

"It's over, Tom," Dumbledore intoned into the silence of the dark, early morning. "That snake was the last one."

"You lie," Voldemort hissed in response, right eye twitching in the wandlight as he turned slightly to try to take in both Harry and the old man. His bone-white skin was so reflective it seemed to make him another light source, while the headmaster was only really visible as a shadowed face within his silvery hair and beard.

Dumbledore had not lit his wand, but had it readied to resume the battle at any moment. "You know I don't. You're mortal again. Harry's been to the other side and back to prove it."

"There is no coming back!" the lich bellowed. "If not for me, then certainly not for Potter!"

Harry stowed his melee weapons and insisted, "I wasn't technically dead," He'd felt like it was a good time to chime in. "You destroyed the other one of those things you put in me, probably without realizing it. So that makes seven of them." He tried a taunt, "Which is confusing, since we thought you were only trying to make six." He swapped the Elder Wand into his main hand, and, with no better idea for an off-hand weapon, grabbed his original phoenix-cored wand and hid that arm behind his back in case the surprise would be useful.

The mightiest dark wizard of his generation processed that information quickly. They knew about his seven-part soul. Potter had been a horcrux? Had he exceeded the limits even he had set for himself, or had some of his anchors been destroyed before he made Nagini? How thinly had he sliced his own soul, and was there enough left to create a replacement anchor?

All of that was calculated in a couple of seconds. It only took that long to come to a decision, "I'll make another with your death! Morsmordre Maxima! Kill them all!"

And, just like that, it was back on.

The spell that Voldemort had cast, which Harry was only vaguely aware of, was a poison-green glow erupting from the tattooed forearms of each Death Eater. A cloudy apparition of a skull woven with a snake appeared in the air above the clearing, illuminating everything in its viridian glow. This floating dark mark seemed to be pulsing in time to the matching glow in the arms of the mages below.

Their health bars slowly began to tick down to power whatever enhancement spell Voldemort had activated. Several stunned Death Eaters woke and struggled to their feet under the torturous buff.

All of that was only background because Voldemort had turned his focus onto Harry a moment after activating his spell. The young video game protagonist was immediately having to dive and dodge for his life as a barrage of curses he'd never heard of sailed his way as the opening salvo. Dumbledore was too busy trying to help the Order of the Phoenix contain the rest of the newly-revived-and-empowered dark wizards to fully engage the lich. "Dodge while you can, Potter! It won't save you," the villain taunted, though seemed impressed and upset that none of his spells had landed. Some of them were fast, and none were as predictable (and seemingly fallible) as the killing curse. He began weaving an area-of-effect attack so that dodging would be useless.

And was Harry hallucinating hearing a full orchestra with a boy's choir singing Latin in the background?

Somehow, he didn't think that his slightly-precocious spells were going to cut it, but he tried all the same. "Incendio! Stupefy! Expelliarmus! Glacius!" With the Elder Wand giving him fast regeneration and maybe helping his casting speed, he rattled off all four in an impressive near-combo. With his Finesse, they each streaked unerringly toward Voldemort's center of mass. And the lich smirked as he batted them away with the tip of his wand, barely pausing in the spell he was weaving.

But a bare pause was a pause. Harry was at least slowing down whatever attack the dark lord was forming.

Maybe he could slow him down enough to wait for the headmaster to fully tag back in. The old man was sometimes throwing a spell Voldemort's way (which slowed his casting even more than Harry's charms), but was about a dozen yards away in the background trying to keep any of his friends from taking a killing curse. Some of the visiting aurors to the other side of the clearing hadn't been so lucky as to have an archmage protecting them. The Death Eaters weren't trying to run anymore, they were trying to wipe the entire enemy force so their leader would turn off the dark mark before it killed them all.

Part of the problem was that instancing was kicking in. Everyone but Harry and Voldemort had become a vague blur against the emerald-and-spell-lit clearing. It was hard for anyone else to focus on the duel between prophesied foes. It might be saving Harry from taking a curse in the back from a Death Eater, at least, for all that it was keeping him and the lich locked together.

He'd cast twenty spells in about as many seconds, and it felt like twenty minutes. Each one forced Voldemort to recover slightly, but his face was getting increasingly smug as Harry couldn't summon up any magic that could get past his point-defense shielding. He was taking the time to error-proof his summon, ghostly flames beginning to wreathe him as he prepared his attack. Could the Elder Wand ensure Harry won a duel if the opponent wasn't dueling so much as preparing an apocalyptic AoE?

With a final grimace of hatred and satisfaction, Voldemort incanted, "Pestis Incendium." Fiendish flames rose around him into the form of an immense serpent and leaped forward along the lich's wand as he gestured toward Harry.

"Protego," Harry tried, moments before the spell launched, thinking maybe the Elder Wand could make a shield strong enough to let him survive the coming flames. But a part of his brain saw the word "fiendfyre" in the combat log and remembered Lupin mentioning how unstoppable it was. Main hand committed to the shield, almost by reflex Harry raised his original wand from behind his back and added, "Expelliarmus." Maybe it would make the dark lord have to move his wand to block enough that he'd miss?

Neither of them could have expected what happened. The music Harry was only half-sure he was hearing crescendoed, becoming a phoenix cry as the light of the disarming charm met the spearpoint of the diving fiendfyre serpent that was lancing toward the Boy-Who-Lived. Along the way, the charm burst through the web of the Elder Wand's shield spell, dragging it along. They collided in a tremendous cloud of golden and flame-red sparks, the light of the shield spreading out to catch the fiery snake in a net of coppery motes.

Harry was holding both wands forward with all of his might, each streaming a beam of light into the combined spell. Voldemort was similarly grasping a literal fire hose, his own fiendfyre streaming from his wand tip and somehow unable to escape the synergy of brother core and deathstick, ultimate burning offense countered by pure defense.

The serpent of flames spent a moment wound in the net before red and gold erupted upwards and hit the boundaries of the instance, roiling down the sides in a dome of light and fire that confined the two destined rivals. As the instance surged to contain the effect, everyone else in the clearing remembered the two were there just in time to be fully blocked from attacking them.

Voldemort was perplexed, once again, by these powers that he knew now. Not even a child's accidental magic should be able to pause the magic-devouring fiendfyre, let alone transmute it into some kind of energy dome. And the boy must have had the fastest and most accurate reflexes in the world to have twin-cast like that at his age. Their wands were still connected by the blazing rope of light. The dark lord couldn't release his hand nor stop pouring in power, hoping to make the crimson flame that coated his half of the connection flow forward.

Harry was similarly bound. Brilliant golden light poured into the phoenix-and-holly wand and through his off-hand, his fingers clenched closed like he had shoved a fork into an electrical outlet. There was no way out but winning this magical tug of war.

Except.

After the initial torrent that had bound the fiendfyre, the Elder Wand was simply assisting. It wasn't locked into the Priori Incantatem. He realized that he might start losing ground on the contest of magic if he moved it, but he could move it. And Voldemort couldn't cast any other spells of his own.

"How? What have you done?" Voldemort snarled.

"I've become the Master of Death, I think," Harry shrugged, a little awkwardly with one arm locked into the spell. "And he doesn't seem to like it very much when people try to cheat him. Expelliarmus."

The lich couldn't move his arm to deflect the spell if he'd wanted to, and with both of them holding still and only a few yards apart, Harry couldn't miss, even with his enemy's attempt to twist out of the way. The disarming charm powered by the Elder Wand hit a hand locked onto a conflict of magical cores and forced it to release and relent.

Several things happened at once.

First, Voldemort's own phoenix-and-yew wand tore free of his hand. But it didn't stop the torrent of energy. With no magical focus to modulate the flow, nothing was left but the lich's hand. Which exploded. The wand sailed on the eruption into the burning dome.

Second, that very dome shattered as if due to the impact of the flying wand, but probably because there was no longer a duel of wills keeping it in place. Shredded into many lines of incandescence, a hundred fiendfyre serpents began to look for something to consume.

Third, no longer opposed by its brother core, Harry's beam of light slammed the remains of Voldemort's spell down the line and into his burned and shredded arm. The negative mystical pressure gave the remnants of the fiendfyre spell only one logical place to go: back into their summoner.

Harry Potter wins Priori Incantatem with Tom Riddle.
Tom Riddle takes [OVERFLOW ERROR] fire damage.
Tom Riddle defeated

Fortunately, Harry's backwards dodge was very effective at escaping the impossibly-hot chunks of a fiendfyre-exploded lich.

Even in their dark-mark-tortured state, the remaining Death Eaters had paused to look at the fiery dome that was containing their master, and, with his defeat, the spell motivating them expired. As the emerald glow around their arms faded, the twentyish remaining dark wizards, their hit points perilously low from the spell's drain, promptly collapsed back to unconsciousness. Those that looked like they were going to stay upright caught stunning spells from the more quick-witted Order members.

With the fight seemingly over, he could no longer hear the music (if he ever had), and everyone just kind of stood around baffled. As far as he could tell, all his friends were still alive and conscious, though some were nursing curse wounds. "Is it over?" he asked, more for the game system than anyone standing around even more confused than he was.

SECRET QUEST COMPLETE
1000 XP Earned
Quest Reward: Increased favor with Death

4864 Combat XP Earned
NEWT Combat Magic XP Earned
NEWT Charms XP Earned
Basic Dodging XP Earned
Basic Swordfighting XP Earned

He hadn't been that far into sixth level, so it wasn't enough to level up, but he was close. He almost certainly would when he went home and finished the quests. Regardless, that combat XP award was a very big number. A larger number than he'd gotten for a fight before. If he'd gotten 800 for a level 20 basilisk split several ways and Voldemort had been close to the same amount of XP, it probably hadn't been split with Dumbledore or his party, despite all the work everyone else had been doing…

"Uh. Sorry for kill-stealing?"

Stay tuned for the denouement and conclusion!