William's proposal sounded reasonable.
Since everything has already been laid bare and everyone has expressed their stance, and William has also stated that due to the special nature of his identity, there's no way he would cooperate with someone like Voldemort who seeks immense power. Even if Dumbledore still harbored doubt, the original plan was already wrecked—
So, at this point, Grindelwald's stay or departure became a problem.
"... Letting a Black Wizard who once led a wizarding revolution stay at Hogwarts, even if you say he's lost all his mana, I still wouldn't be at ease."
William shook his head, indicating that he couldn't possibly allow such a dangerous character to freely roam the school. It's like standing beneath a dangerous wall; even if Grindelwald has reformed or even become a monk, he is still the type of dangerous person who requires close monitoring.
But what is Dumbledore's attitude? A laissez-faire approach?
Moreover, it's now confirmed that the ability to perceive Ancient Magic is not innate, which means there's risk for anyone approaching the Secret Vault.
William considered himself not inferior to any wizard with abundant resources when it came to magic power, and with those aces up his sleeve and powerful charms, he was very confident in his combat prowess. But this world's magic system wasn't like some fantasy novel, where William could simply seize and refine Hogwarts in an instant...
A single unchecked Killing Curse or even a bullet could easily take his life.
Moreover, it's hard to guard against thieves every day. Someone like Grindelwald, a dangerous element, is best thrown back to Austria, strengthening his cell while at it—"Of course, if you're unwilling, I do have a vacant cage."
Noticing Dumbledore's silence, William wasn't anxious. He spoke leisurely.
It's best not to push the old man too hard; if we can avoid turning against each other, it's all for the best. The plan to solve the Voldemort problem still needs someone in the front to take the heat... or rather, draw attention.
"You have quite an issue with me."
Grindelwald wasn't an idiot, so this statement had a definite tone. He already sensed the undisguised tone in William's words, with its underlying jabs, making him unconsciously frown, as if pondering whether he'd offended the other party somewhere...
Probably not, just made him attend an extra class each week, is it enough to get him so worked up?
If it were in the past, even less likely, because with the time lost, the two had no interaction a century ago, let alone enmity—
But if William could hear the old man's thoughts, he might say: Yes, I am that worked up—what's the matter with your teaching? You teach math, physics, and chemistry? Even assigning homework and essays, who taught you to study Muggles like this? He recalled his high school days before classes were divided, tormented by math, physics, and chemistry, forcing William to frown.
Of course, these were just secondary factors; the main issue was undoubtedly Grindelwald's actions during the revolution period.
Purge party, repeated terrorist attacks, the Paris fire, attempts to provoke a wizarding world war, sporting a little mustache, speaking native German...
He even displayed slight tendencies toward genocide later on.
Even the timeline of complete failure roughly matched the 1940s.
Another him in this world?
Similarly, the countless blood debts Grindelwald bore couldn't be washed clean, and William had always held contempt for those who massacred the innocent. He wasn't a stranger to killing, and perhaps he had personally killed more people than the combined tally of the two Dark Lords, but he would never kill innocents.
Even for the Ashwinder Party, he merely dealt with the beneficiaries; any others were stripped of magic, had their memories erased, and thrown into the mountains to become farmers.
After all, the Ashwinder Party was essentially Rookwood's family business, not without minors among them—whereas poachers were different, these bastards didn't just hunt animals, so dealing with these traffickers incurred no psychological burden for him.
"So clever, knowing even this."
William smirked lightly, his expression causing the baffled Grindelwald to take a deep breath, saying nothing further, but rather looking down at Dumbledore.
And coincidentally at that moment, Dumbledore also raised his eyes, exchanging a glance with the other elder, exchanging volumes of information—
"Albus, what's your thought?"
Grindelwald's tone was quite humble, sounding as if he would completely defer to the other's decision.
"You can stay, but I need some protective measures..."
William's tone softened a bit. While he thought Dumbledore might have grown somewhat senile recently, he still needed to provide a way out—
"Protection measures? We have them, William, we have them."
Dumbledore abruptly stood up, unveiling the wizard robe draped over the coat rack beside him, revealing a red "lantern" about the size of a football in front of William.
... What on earth is this?
William remained silent for a moment, his eye twitching slightly. Watching the color of the red sphere, the silver-white metal casing around it, and the silver chain tied to its top, a hypothesis suddenly formed in his mind.
"... A Blood Alliance?"
"Yes."
"... But why is it so large?"
William rubbed his brow, this vow that existed in their relationship was quite abstract, but... isn't this a bit too abstract?
"Because, there are quite a few rules we drafted."
Grindelwald added blankly, while under William's slightly puzzled gaze, Dumbledore, returning to his seat, opened a drawer and handed a parchment filled with dense clauses to William, whose eyelid couldn't help but twitch at the sight.