Watching from the sidelines, Dumbledore could see clearly that Isaac had controlled the entire duel from start to finish.
If an ordinary wizard wanted to deal with a Seer who could "read the script" at any moment, a spell like Stupefy simply would not cut it.
As long as the Seer was on guard, even a Killing Curse was useless if it missed, let alone a Cruciatus Curse.
There was only one way for the dark wizard to beat Isaac.
Cast offensive spells over a wide area and wear Isaac down with their AOE.
Unfortunately, that approach ran counter to the dark wizard's reason for coming.
The very first spell the dark wizard had cast upon seeing Isaac was Stupefy.
That meant hurting Isaac was not the primary purpose of his visit.
He wanted to subdue Isaac.
Isaac had easily dodged Stupefy, and none of the three consecutive Cruciatus Curses that followed had hit him either.
Then came half a Killing Curse—Dark Magic really had scrambled this dark wizard's brains. Any ordinary wizard would have realized something was wrong by then.
Either leave or change tactics.
Yet he stubbornly insisted on swapping the Cruciatus Curse for the Killing Curse.
If he could not hit his target, even an Avada Lightning Chain would not do a damn thing, never mind a Killing Curse.
Finally, there was Isaac's spell, Protego Fiendfyre.
Aside from its color and power, the Waldore Gas Stove was no different from the original Grindelwald Gas Stove.
Isaac's casting movements, combined with his three signature Grindelwald traits...
For an instant, Dumbledore had almost thought he was watching a young Grindelwald fighting someone.
Protego Fiendfyre was Grindelwald's spell, one of the signature techniques of master wizards like them.
Unless Grindelwald had taught him personally, Isaac could never have learned that spell on his own with his current knowledge.
Not even a cut-down version that merely combined a Fire-Making Spell with Transfiguration.
So this spell was Grindelwald's "greeting" to him.
Who will love you now, Dumbledore?
There was no time left to mourn Dumbledore's lost love. Next to Apparate onto the scene was a trio of Aurors from the British Ministry of Magic's Auror Office!
Three Aurors Apparated into Isaac's yard. The moment they "landed," they saw Dumbledore and Isaac standing in the hall.
Startled, all three hurried toward them.
"Professor Dumbledore, we received an alert that someone here was using Unforgivable Curses.
"What exactly happened?"
Dumbledore turned to look. They were all familiar faces.
"Gladwin, Kingsley, and John? It's been a while. How have you been?"
The arrivals were Gawain Robards, Kingsley Shacklebolt, and John Dawlish of the Auror Office.
Gladwin was the trusted deputy of Rufus Scrimgeour, the Head of the Auror Office.
He was effectively the Auror Office's second-in-command.
If they had not detected a wizard using Unforgivable Curses in a Muggle area, they would never have sent such a high-level investigative team.
"Er... fine, Professor.
"So what exactly happened?" The three Aurors entered Isaac's house, only then noticing a wizard lying in the hall, his condition unknown.
Isaac, Dumbledore, and a dark wizard—a lineup spanning three generations, coupled with an outbreak of Unforgivable Curses...
Perhaps their experience as Aurors was limited, but they truly had not seen anything like this since Voldemort's "death."
"Well, here's what happened... I received a letter from Mr. Isaac Waldore in my office today, saying that a wizard had set his sights on him.
"So I hurried over to his house.
"But I was still too late. By the time I arrived, Isaac had already subdued this dark wizard."
Gladwin realized that this boy probably held the key to the truth, so he asked kindly:
"Waldore... oh, do you mind if I call you Isaac, lad?
"Could you tell me exactly what happened?
"How did you subdue this criminal?"
Isaac was surprised that Dumbledore had actually left out part of the truth.
According to Dumbledore's account, Isaac's adventure had gone from a venture under Dumbledore's supervision to a fledgling hero taking up his sword against evil.
Although Isaac did not understand why Dumbledore had done this, he knew Dumbledore must have had his reasons.
Compared with these three Aurors, the two of them were on the same side.
"It all started in Diagon Alley..." Isaac began with how he had noticed someone following him in Diagon Alley.
He went from discovering he was being followed to borrowing an owl from the owner of the Owl Emporium to send Dumbledore a letter.
Then he described leaving Diagon Alley and returning home.
Isaac had never expected the dark wizard to dare come straight to his door.
Since Isaac did not yet know any magic that would let him escape, and Dumbledore still had not appeared at his house, he had been stuck.
He could only find a way to deal with the dark wizard himself.
"I dodged his first spell, then used a Levitation Charm..."
Isaac continued all the way to the final "spell he had invented," Protego Fiendfyre.
Listening to him, Gladwin felt his entire understanding of the world being overturned again and again.
Especially when he heard that Isaac had dodged three consecutive Cruciatus Curses and forced half a Killing Curse back down the dark wizard's throat. He began looking at Isaac in a whole new light.
Could this boy be a young Dumbledore?
Isaac's story sounded absurd, like a third-rate tale of wizarding adventure.
Yet Gladwin knew that, in this world, the more absurd something sounded, the more likely it sometimes was to be true.
"You did wonderfully, Isaac! At your age, I didn't even know a single spell."
Gladwin first praised Isaac, then put on a helpless expression.
"But according to Ministry of Magic regulations, we still need to examine your wand. Would that be all right?"
"Of course, Mr. Auror."
Isaac nodded and handed his wand to Gladwin.
Gladwin took out his own wand and pointed it at Isaac's.
"Prior Incantato!"
The first spell revealed by Prior Incantato was Protego Fiendfyre.
Gladwin was an elite member of the Auror Office, after all. Unlike employees in other Ministry departments who could not even cast Protego properly, he could more or less see how Isaac's version of Protego Fiendfyre worked.
"A variant of the Fire-Making Spell that combines it with Transfiguration?"
He waved his wand again, revealing more of the spells Isaac's wand had cast.
He continued all the way back to when Isaac had been repeatedly practicing Transfiguration.
Gladwin glanced at Dawlish, who nodded to indicate that everything had been accurately recorded.
"Thank you for your cooperation, Isaac. Here's your wand."
They had finished examining one of the people involved. Next came the dark wizard on the floor.
While John Dawlish recorded the spells from Isaac's wand, Kingsley began examining the dying dark wizard on the floor.
"Robards, you need to see this!" Kingsley lifted the dark wizard's left forearm, showing its inner side to his superior.