Avada Kedavra!
The Killing Curse. The worst of the three Unforgivable Curses. A spell designed specifically to sever the soul from the body.
As the incantation left Rey's lips, a jet of blinding green light erupted from the tip of his wand. Like a bolt of lightning, it struck Dorry squarely in the chest.
This curse targets the soul. To cast it successfully, the caster's intent to kill must come from the depths of their own soul.
Moreover, Avada Kedavra is the precursor to creating a Horcrux. When used to commit murder, it doesn't just destroy the victim's soul; it rips the caster's soul apart.
Killing this way was nothing like Rey's act of self-defense in the alley. It carried a weight that went far beyond mere psychological guilt.
Aside from its soul-shattering properties, no one had fully researched the other side effects of the Killing Curse. Perhaps even Voldemort only used it for its lethal efficiency and its utility in creating Horcruxes.
To cast it requires immense magical power and a resolve that permeates the soul.
Typically, someone who can instinctively control their magic before any formal training possesses a significant reservoir of magical power.
Rey was one such person. After researching the spell in the library, he met all the criteria. Now, backed into a corner and fighting for his life, he was able to unleash it.
The green light slammed into Dorry's chest. Rey had poured a massive amount of effort into the spell, so the flash didn't vanish instantly. It lingered for at least a full second, only fading after Dorry had collapsed completely.
Rey felt the drain on his magic. Using such high-level dark magic for the first time took a toll.
He gasped for air. The magical exhaustion wasn't as severe as he had feared, but using the Killing Curse left him with an inexplicable tension, a profound weariness that settled into his bones.
Dorry was down. It seemed over. Rey kept his wand raised, pointing it at the body on the ground.
Rey didn't know if his soul had split.
Even if it had, he didn't know what that felt like, nor was there any way to check. His only concern right now was whether Dorry was actually dead.
Because that man's resistance to magic far exceeded anything a human wizard should possess.
He must be dead, Rey thought. He has to be.
Avada Kedavra is unblockable and incurable. Unless someone sacrifices their life to cast a protection charm born of love, or unless the spell hits a physical barrier, or unless the wands share a twin core... death is certain.
Dorry didn't meet any of those conditions. The only reason Rey still held his wand on him was that he hadn't fully recovered from the shock of unleashing that green lightning.
It was his first time. The impact on his soul was jarring. And amidst that shock, Rey felt a faint, disturbing flicker of excitement... and a sliver of dark satisfaction.
Dorry was a seasoned professor. Whether he was turning into a vampire or not, his power was real.
And Rey was just a first-year. A first-year who had taken down a Defense Against the Dark Arts professor. Any way you sliced it, feeling a bit of pride was understandable.
But that excitement... that smug satisfaction... was that how a normal person should feel after killing someone?
A normal person should feel horror. Even when Rey killed the mugger in self-defense, he hadn't felt this.
This feeling permeating his soul was definitely not something to celebrate.
Rey lowered his hand, his mind on high alert. If he were just a child, he might have let that feeling fester. But as an adult soul, he recognized the danger and clamped down on it immediately.
This was exactly why Dumbledore had asked Snape to kill him, rather than letting Draco Malfoy do it. He wanted to protect the boy's soul from being completely corrupted by the act of murder and the allure of the Dark Arts.
"I shouldn't use this spell unless I absolutely have to. Ideally, never again."
Sensing the corruption within the magic, Rey made a silent vow.
With Dorry dealt with, the next step was to wait for Hagrid. He should be arriving any minute now.
Rey also worried about the Trace.
Underage magic outside of school was detected by the Ministry. But inside Hogwarts? Or in the Forbidden Forest? He wasn't sure if using an Unforgivable Curse here would trigger an alarm.
Using one of the Unforgivable Curses meant a life sentence in Azkaban. Rey was naturally anxious.
---
"That... was truly an unforgettable experience."
A low, raspy voice suddenly broke the silence of the night.
It was Dorry. As he spoke, he sat up abruptly. His movements were fast but jerky and stiff, mirroring the unnatural smile that had been plastered on his face.
The silence of the Forbidden Forest shattered. Dorry sitting up startled Rey so badly he nearly jumped out of his skin.
"You're not dead!"
Rey gasped in disbelief. Victims of the Killing Curse die. That's the rule. Yet Dorry was alive.
"Heh. I should be dead. I don't know why I'm not."
Sitting on the ground, Dorry suddenly raised his wand with blinding speed and pointed it at Rey. "Stupefy!"
The attack was so sudden that Rey only had time to instinctively throw his arm up to shield his face.
Against a spell, blocking with your arm is useless—fatal, even. But everything happened too fast. Who could have predicted a corpse would sit up and fire a spell?
---
The incantation was spoken, but the spell didn't work.
No red light shot from Dorry's wand. The Stunning Spell failed completely.
Rey couldn't believe it. Dorry couldn't believe it either. How could a professor fail to cast such a basic spell?
Leg-Locker Curse, Sectumsempra... after the Stunning Spell failed, Dorry tried several more. All of them failed.
"Could it be..."
"You're already dead."
"I am already dead."
They spoke the realization at the same time, though with different pronouns. Rey and Dorry instantly understood why the magic had failed.
Whatever the cause—perhaps a vampire bite—Dorry's body had been dying, his soul slowly dissipating or transforming into the energy that fueled undeath.
A vampire's body is cold and feels no pain, but unless destroyed by external force or sunlight, it is immortal.
Avada Kedavra attacks the soul, forcing it to sever from the body, causing death.
But Dorry's soul was already in the process of transforming or dissipating. Being hit by the Killing Curse might have accelerated the process, or perhaps it destroyed the part of his soul that hadn't yet transformed.
Biologically speaking, Dorry had fully turned into a vampire. He was dead. Therefore, Avada Kedavra hadn't failed; it had simply hit a target that was no longer alive.
"FUCK!"
Dorry roared, unable to accept the truth. He launched himself from the ground, blurring into motion.
The moment he moved, Rey's vision went dark as he was sent flying backward.
Dorry was faster than before. At such close range, even if Rey could see him coming, his body couldn't react fast enough to dodge.
Rey was punched through the air, rolling several times before coming to a stop.
Clutching his chest, Rey coughed violently, shaking his head to stay conscious.
He still held his wand. As long as he could aim one more Avada Kedavra at Dorry, Rey believed that even a vampire wouldn't walk away unscathed.
Dorry stood over Rey, his cold eyes wide with surprise. He had used his full strength. An ordinary wizard would have been killed by that punch. Yet Rey staggered to his feet and raised his wand again.
"Avada Kedav—"
Before Rey could finish the incantation, Dorry's hand clamped around his throat, lifting him off the ground single-handedly. The curse died in his throat.
"Trying to use the Killing Curse again? You overestimate yourself. Even if I am a vampire now... your blood can still make me a king among my kind."
Dorry roared in frustration, opening his mouth to reveal sharp fangs. He snapped his head forward, aiming for Rey's jugular.
---