Sure, here is the translated text:
Moreover, if this is the old estate of the Black Clan, then it means—
Standing in the living room on the third floor, looking at Phineas Black who was staring at him with a sulky face, William smiled, "Long time no see, Headmaster."
"...Why are you here?"
After a moment of silence, Phineas asked with an unpleasant expression. Due to his infamous reputation, there were not many portraits of him left in the world, probably only one in the Hogwarts Headmaster's office and one here. Ever since William became a frequent visitor to the Headmaster's office, he seldom stayed there to avoid being stealthily dealt with by William, and yet...
Why is this person so persistent?
"Perhaps it's fate. You seem to be doing quite well."
William said with a smile and open eyes, the truth hidden in his lies. The frame hanging on the wall was obviously somewhat in disrepair, the golden inscriptions nearly completely peeled off, and even the spirit of the Black in the portrait seemed somewhat listless.
"Haha, very funny, isn't that thanks to you."
Phineas laughed without any emotion, glaring at William, he questioned, "So, why are you in the old estate of the Black family?!"
"Of course to catch your great-great-grandson."
William smirked, glancing at the study behind him, he didn't linger any longer but said to the portrait, "Alright, since you're here. In a bit, you might have to run to the office, tell Dumbledore the location here, and bring Lupin along."
"Why should I listen to you?!"
Blake's face turned red, obviously infuriated by William's demands—
"Honorable Mr. Black, you wouldn't want your family to simply perish, would you?"
"..."
William's words successfully struck the core of this old man who valued the honor of pure-blood and family above all else. It even caused an immense impact upon him, and the old man could only struggle to glare at William before turning away from the frame.
...
...
Pain.
Severe pain.
The five senses unique to humans re-entered the man's mind, chaotic thoughts reoccupied the high ground. He subconsciously wanted to struggle, but found his whole body seemingly bound inch by inch, even to move a finger required all his strength.
The scent of incense rushed into his nasal cavity the next moment, and Sirius Black opened his eyes.
Then, he found himself sitting on the sofa in his own study, dim light flickering on the bookshelves. The man squinted his eyes, trying to discern. After a while, the brain that had just completely shut down restored the link; it seemed like some kind of incense?
Hmm… it smelled that way too.
The scent of blood mixed with a somewhat dizzying aroma, Sirius felt it seemingly suppressed the pain on his body… Hmm? What was over there? Sirius tried to turn his head, but the stone-like stiffness of his neck told him it was impractical, so he could only use his peripheral vision with effort—
"...Kreacher?"
His voice was a bit hoarse, the intense dryness and pain in his throat made him uncontrollably frown.
"It is dead."
A voice like a devil's sounded above his head in the man's ears, then the sound of a book closing followed, William circled out from behind the sofa and sat on the sofa opposite Sirius, "To protect you..."
"That's a damn lie."
Sirius spit forcibly, his expression very disdainful, "It? To protect me? Haha, this is the best joke I've heard in the past decade." After speaking, he glared at William relaxedly sitting on the sofa, his tone full of ridicule, "Stop BSing with me, what are you really…"
"Scourgify."
William frowned and fanned his nose, then tapped his finger, a bunch of pink bubbles surged from Sirius's throat. The man coughed forcefully, holding his throat—at this moment, he suddenly realized he could move? The man's gaze shifted, looking at the seemingly defenseless boy opposite…
"Bang!"
A dull sound came from behind the man, he turned silently to look, and met the golden eyeholes of a tall Magic Rune Stone Statue.
"It's called Big Yellow, say hi?"
William chuckled lightly, as if amused by Sirius's reaction.
"Cough cough, you..."
Daring not to move anymore, Sirius coughed a few times, spitting out all the pink bubbles in his throat. He had never thought such a thing would happen to him, remembering he had done this to others back in school…
"I wasn't lying to you, it really was to protect you, after all, you're the last male heir of the Black clan in this world…" William's voice sounded somewhat dreamy.
"I certainly did not give it that order!"
"But, it still follows your mother's orders, that portrait…"
"You mean that old woman? Haha, she wishes I would die immediately—" Sirius's tone was extremely sarcastic.
"But she is still your mother."
"...Stop it."
"Ah, the great maternal love! She puts her own life on the line, even if just the life of a wall painting, orders to save you, wonder if she has any other backups…"
"I told you to stop…"
"Alright, just kidding."
"?"
Sirius's face froze in grief then began to crumble, he looked at William somewhat confused.
"The elf didn't die, caught it because it tried to flee here, and your mom doesn't love you at all. By the way, that portrait was incredibly annoying, hey? How do you endure living under the surround sound of hundreds of ducks? Could it be that you went to Azkaban to actually dodge her?"
"...What do you really want to do?"
The barely risen mental barrier was shattered yet again for Sirius, he paused for a moment, looking at William with some bewilderment.
"Ask some questions, before the Ministry of Magic comes to throw you back in Azkaban." William paused, "Of course, given the current Minister's petty nature, he is more likely to reward you with a Dementor's Kiss, congratulations, that's a rare achievement."
"...I want to see Dumbledore."
"Oh, how odd, is Dumbledore some kind of high official overload? I didn't see any crescent moon birthmarks on his forehead?"
"Before seeing Dumbledore, I won't say another word, you can kill me."
Sirius Black lowered his head, his entire being exuding a clear reluctance to answer.
"No, you will."
William shook his head and then continued speaking despite Sirius's mocking glance, "Name?"
"Sirius Black..."
"Gender?"
"Male."
"Underwear color?"
"...Not wearing."
"?"
Alright, this time even the confused people numbered two.
Unlike William's trivial distraction, Sirius's expression began turning fearful. From answering the second question, he had already covered his mouth, but the muddled answers squeezed out from between his fingers made it into both's ears.
"Aguamenti."
William kicked towards the floor, pushing himself and the sofa back half a meter, then used Aguamenti to wash Sirius from head to toe. Hence, this street beggar who originally looked somewhat dirty finally revealed a slightly handsome face despite being skinny.
"Cough cough. What did… you do to me… cough cough?"
Sirius coughed hard, chilled water incidentally filled his mouth, nearly choking him.
"Veritaserum incense, how do you feel?"
William pointed to the incense placed on the shelf, seemingly inconspicuous, and looked at Sirius, continuing to question him, "So, why were you lingering around Hogwarts? Was it to kill Harry Potter?"
"...No."
"Then why?"
"It was… for Peter Pettigrew!!"
Sirius seemed to resist, but the effects of the Veritaserum still forced him to answer, he could only do so through gritted teeth, and when mentioning that name, his voice was full of an uncontrollable grudge.