"My mind is my kingdom." — Francis Quarles
Regulus had been incredibly busy since his magical outburst. He began browsing the books available to him in the Black family library. Some of these tomes contained Dark Magic so potent that they could make people writhe in pain, freeze in fear, or even die simply by touching the cover. Naturally, those books were stored in the most secure archives, inaccessible to Regulus—for now.
Regulus absolutely despised the introductory textbooks recommended by Hogwarts. Compared to the ancient grimoires of the Black family, the standard curriculum was utter rubbish. However, courtesy of Mr Carrow, he had no choice but to start with the basics.
He began with the fundamental theories and simple spells. Still, he could not use them openly, as he did not yet possess a wand.
In his private time, he practised Lumos, Wingardium Leviosa, and household charms like Scourgify and Reparo by himself, without a wand. His progress would have been much slower if not for his ability to sense magic. He observed the patterns and shifts in the magical atmosphere around his teacher and tried to imitate them. It took him a week just to get in sync with the Lumos charm.
Through this, he came to understand a distinction: the "Spell" was the incantation—the verbal component—while the "Charm" was the corresponding manipulation of magic that made the desired effect manifest.
The start was slow. But as he continued to put in the work, he progressed faster and faster, until his improvement was almost instantaneous. He realised his real gift was simply the ability to work hard to make the task easier.
He jokingly thought of naming this gift 'Work Hard to Gain Power.' But eventually, he settled on a simpler name: 'Adept'—signifying his capacity for rapid learning.
A month later, he could use all the spells he had learned instantly and cast silent charms with ease. He progressed in the study of potions, too. He observed how every ingredient altered the composition of the brew; he learned when and how to stir by relying on his enhanced senses. His sense of smell and taste helped significantly in this regard.
He was also taught the theory of the three Unforgivable Curses: Imperius, Cruciatus, and Avada Kedavra.
Mere mention of these spells made the ambient magic restless. To Regulus's eyes, the usually milky-white, translucent fog of magic turned a turbulent dark grey before returning to normal.
He decided not to attempt those curses too soon. However, he knew that Dark Magic was unavoidable for a Black.
When Regulus reached the age of six, he received a training wand from Knockturn Alley. It was a gift from his teacher, who had personally checked the materials to ensure they were suitable for him.
The wand was made of Elder wood with a core of Thestral hair. It was a combination representing a power undefeatable, even in death.
Mr Carrow was certainly pleased with this combination and pushed him to study even harder—something Regulus was very much used to by this point.
For his sixth birthday, Regulus met with his brother and cousins. Sirius was almost unrecognisable. He wore a hateful glint in his eyes that made him seem far more intimidating than before he had left for school. Sirius hated his family for forcing him to attend the Nostradamus School, but as the Heir to the House of Black, he had no choice but to return until he was eleven.
The cousins were becoming unrecognisable, too. Andromeda was growing more distant, Narcissa was losing her childish innocence, and Bellatrix was becoming a vocal supporter of Pureblood supremacy.
During this time, Kreacher happened to catch Regulus using wandless magic during one of his private practice sessions. Kreacher mumbled something in awe, but Regulus ordered him not to disclose this information to anyone. Since Regulus had never ill-treated him, Kreacher held extra affection for this young master. He served many masters in the House of Black, but he devoted himself to Regulus without complaint.
The start of Occlumency training was a cat-and-mouse game. Mr Carrow was not permitted to teach it, as the family could not risk an outsider accessing the secrets inside the heir's brain. Therefore, Arcturus himself took over the instruction.
…
Regulus POV
"Grandpa, you called me?" I asked politely as I entered the study.
He was sitting in his usual high-backed chair, reading parchment containing information about the Wizarding World—documents I had secretly tried to peek at before.
He closed the parchment and said, "This is too early for you. I called you regarding your lessons with Mr Carrow. How is he teaching you?"
"Mr Carrow has taught me almost everything I needed to learn before going to Hogwarts. I have even started learning first-year spells and potions with him. He wanted to teach me Occlumency on the spot but refrained at the last moment."
"Good. Occlumency involves peeking into the mind. He is not fit to teach it to you. We are going to start learning it right now," Arcturus said with absolute command.
I started to panic. My memories contained secrets—my past life, my system, my plans—that would leave me exposed if discovered.
"I am going to start with Legilimens, which will invade your mind. You must try to defend yourself," he said.
Before I could prepare, he started probing my mind. I could almost see his spectral presence trying to breach my mental walls. I collected all my willpower to push him out, but he noticed my panic and my surface thoughts.
"GET OUT!" I yelled in sheer panic.
The surrounding magic reacted violently to my words, lashing out and expelling Arcturus from my mind with force. He sat back, wearing a shocked expression for a few seconds.
I regained my composure and spoke in an apologetic tone. "Grandpa, I apologise…"
He did not wait for me to finish. Suddenly, he burst out laughing.
He stood up and levitated me into the air with his wand, bouncing me up and down like a rag doll in his joy.
"You are a natural Occlumens! You are powerful enough to expel me from your mind by instinct alone. The Black family has produced another genius!" he ranted on and on, continuing to levitate me.
"You just have to remember the feeling you had when you expelled me from your mind and progress with it," he said.
With that, he gently threw me out of the room without any further warning and the door slammed shut.
…
Behind the closed door, Arcturus dropped the joyous facade. He grimaced in pain and rubbed his temples, nursing a pounding headache.
"That brat is stronger than he looks," he muttered to himself, before a smirk of pride returned to his face.