Dark Magic is fascinating!
Its fire cannot be extinguished by water.
That's right. The first spell Grindelwald taught the young wizard was Fiendfyre.
Three days had passed since then, but Grindelwald wasn't pleased. In fact, his expression grew darker by the day. Why? Because the young wizard had taken Fiendfyre—the legendary, destructive force that Grindelwald had nearly used to burn down Paris—and used it... in the fireplace.
Is this even my Fiendfyre?
It was the same blue flame. It was equally impossible to extinguish by normal means. Yet, the old wizard felt that his version was infinitely inferior to the boy's.
Grindelwald's Fiendfyre manifested as terrifying, struggling faces and monstrous beasts, radiating pure malice. Once unleashed, it was uncontrollable and just as likely to burn the caster as the target.
Owen's Fiendfyre? It manifested as tiny blue phoenixes. They chased each other playfully, chirped on the hour like clockwork, rolled around in the boy's palm, and occasionally circled a mug to heat up his milk.
Not only was it incredibly docile, but it also came with a bunch of convenient features. You couldn't even compare the two.
Watching the young wizard scribble furiously in his notebook, Grindelwald felt old for the first time in his life.
"Sir, can we continue?"
Seeing the old man silent, Owen took it as a yes. He picked up his notebook and launched into his next question.
"The name 'Dark Magic' implies that long-term use affects a wizard's mind and body, darkening their heart and eventually driving them to madness. As the first Dark Lord, you used Dark Magic for a long time. How do you feel it has affected you?"
Grindelwald's mouth twitched. He looked up with a dark expression, ready to snap, but then he met the boy's eyes. They were pitch black, pure, and filled with nothing but a genuine hunger for knowledge. His anger deflated instantly.
"Hmph. That's just the foolish rambling of the weak. Dark Magic's influence on a wizard isn't nearly that dramatic—at least, not for most spells. It is the wizards who corrupt themselves, not the magic."
Owen nodded. He had suspected as much. As the saying goes, "When you hold a weapon, the intent to kill rises." Dark Magic is powerful, fast-acting, and often easier to cast than standard spells. Fiendfyre, for example, doesn't require complex wand movements or precise pronunciation. You just need absolute confidence in your success.
It's easy to get addicted to that power, to become arrogant, and eventually adopt an "I am invincible" mindset that leads to trouble.
So, Dark Magic isn't inherently terrifying as the books say. The terrifying part is, and always has been, the human heart.
Note that down!
A quill zoomed across the page, faithfully recording Owen's thoughts.
"Sir, I want to study the Cruciatus Curse. Could you cast it on me?"
????
A row of question marks practically appeared over the old wizard's head. He stared into the boy's eyes. "Has the Fiendfyre driven you mad?"
"No, sir. I want to experience the spell's specific power and what it feels like to be hit by it."
After triple-checking that the boy hadn't lost his mind, Grindelwald extended a finger toward Owen.
"Crucio."
"Hng!"
The impact of the spell only knocked Owen's upper body back slightly. But the pain that followed was instant and excruciating. His face went pale, but he didn't scream. He only let out a grunt of pain.
What moved the old wizard was that even under the torture of the Cruciatus Curse, the boy held on. And the quill recording the data never stopped. It faithfully documented every sensation Owen was feeling.
Pain!
From flesh to bone, everything hurt.
It felt like countless knives slicing through his body, countless hammers smashing every bone. But the worst part was the twisting sensation in his heart, like an invisible hand mercilessly squeezing it.
Just as he felt he couldn't take it anymore, Owen transferred his consciousness into Whitey, the phoenix perched nearby. Through Whitey's eyes, he watched his own body convulse.
Grindelwald was dumbfounded.
He clearly saw the boy lose consciousness, yet from start to finish, Owen had only grunted once. The most insane part? Even though the boy was out cold, the quill kept writing, recording data at high speed.
Is... is this still magic?
Have I been in here too long? Am I out of touch with modern magic?
When his muscles finally stopped twitching, Owen's consciousness returned to his body. Feeling the lingering ache inside and out, he suddenly smiled—startling the old wizard again.
"Boy, have you lost your mind?"
"Of course not, sir. I just discovered that if you control the output, the Cruciatus Curse is actually quite effective for improving physical fitness."
"Huh?"
Grindelwald understood every word the boy said, but strung together, they made absolutely no sense.
The Cruciatus Curse... improves physical fitness?
Dumbledore, where did you find this freak?
Owen wasn't lying. He had never stopped tracking his physical condition, keeping detailed records. After this bout of Crucio, his muscle engagement was equivalent to a year's worth of morning runs—and it worked every muscle group simultaneously.
Most importantly, his heart felt stronger after the stress test.
The spell was useful, but the pain far outweighed the benefits. Continuous exposure would still cause irreversible damage.
"The Unforgivable Curses... there really is a lot to unpack there."
The pale-faced young wizard picked up his notes and went back to studying, leaving the old wizard sitting there, lost in thought.
---
After a long while, Grindelwald suddenly looked up. "Kid, you only have six months. are you sure you want to waste all your time like this?"
Owen turned back and smiled. "Until you decide to open up, this is all I can do."
As the first Dark Lord, Grindelwald's power was undeniable. Just because he was defeated didn't mean he stopped being a powerhouse.
Even without a wand, Grindelwald could do more than just cast spells. He could cast them silently—using Non-Verbal Spells. And from that skill, he had developed an even more advanced technique: Multi-Casting!
The old wizard's spirit flared to life again, the Dark Lord returning. But he didn't teach Owen too much Dark Magic. Instead, he taught him various casting techniques and engaged the boy in no-rules duels every three days.
With advanced techniques and practical combat training, Owen's progress was visible day by day. The only thing that slightly annoyed the old Dark Lord was that the boy's enthusiasm for studying never waned. No matter how tired he was, Owen insisted on hitting the books.
"Sir, knowledge is the only wealth I have right now that no one can take away from me."