Over the following week, my days were packed with an intense variety of activities, though I dedicated the vast majority of my time to understanding and mastering my demonic power. It was an uphill battle, primarily due to the sheer, overwhelming volume of energy residing within my five-year-old body. The only logical explanation for possessing such an absurd reservoir of power compared to other devil children of my generation was my lineage. As the son of a Super Devil, my baseline potential was fundamentally skewed—much like how Millicas Gremory was naturally more talented and potent than Rias had been when she was his age.
I spent hours testing the foundational elements: summoning fire, lightning, wind, water, and earth. Through careful trial and error, I discovered a clear hierarchy in my natural affinity and control. Wind came to me with effortless precision, claiming the top spot, followed closely by earth. Fire and lightning took third and fourth place, while water proved to be the most stubborn and difficult to direct.
Demonic power, as I quickly learned, did not operate on the rigid mathematical formulas required by human magic. Instead, it was an art governed almost entirely by imagination, willpower, and refined internal control. If I could clearly conceptualize a phenomenon and possessed the raw energy to fuel it, my demonic power would reshape reality to match my intent.
Beyond the basic elements, I branched out into more specialized disciplines, such as gravity magic. With focused effort, I could counteract gravity enough to levitate several inches off the floor, localize crushing pressure onto a single point, or artificially increase the weight of an object by roughly two hundred pounds. However, sustaining these localized gravitational fields drained my mental stamina rapidly. It demanded an exacting level of fine control over my demonic aura that I had yet to master.
Recognizing its utility for physical conditioning, I began applying subtle gravity magic directly onto my own body, steadily increasing my training load throughout the week. While seven days was hardly enough time for a miraculous transformation, there was already a noticeable improvement in my physical strength and endurance. If I maintained this regimen, my capabilities would undoubtedly advance by leaps and bounds.
Biomancy, on the other hand, proved to be by far the most difficult discipline I tackled. Altering one's biological structure required an intricate, intimate understanding of anatomy paired with surgical magical precision. Through biomancy, I could actively reinforce my internal structures, hardening my skin or temporarily dense-packing muscle fibers for enhanced resilience and power.
More importantly, it accelerated my regenerative capabilities. Stacked atop a devil's innate vitality, it allowed minor cuts and scrapes to close seamlessly within minutes. I theorized that severe injuries could be healed within hours, and with sufficient mastery, regenerating severed limbs would not be out of the question.
The major drawback, however, was continuous maintenance. The instant my concentration slipped, any anatomical modifications instantly unraveled. In a life-or-death battle where I would simultaneously need to cast offensive spells and evade attacks, holding that focus would be grueling. ' I should ask Leah if she can fetch me a few comprehensive books on devil anatomy, ' I made a mental note.
Clairvoyance turned out to be another remarkably practical spell. With a bit of focus, I could cast my sensory awareness across the expansive Astaroth estate without ever leaving the comfort of my bedroom. It was an invaluable reconnaissance tool—though I'll admit I found a rather questionable application for it when the maid staff took their evening rotation in the private bathhouses.
"Hehehehe..."
I caught myself mid-chuckle and abruptly scrubbed the foolish grin from my face with an embarrassed cough and a heavy sigh. In my previous life, I had been an introverted shut-in, but having those mature memories and impulses resurface within the body of an aristocratic child created a strange, chaotic blend of temperaments. The merger of memories had undeniably shifted my mindset in subtle ways, though whether that was for better or worse remained to be seen.
I also spent time refining illusion magic, using it for relatively harmless mischief around the manor. For now, my proficiency was limited to small, ephemeral conjurations. Extending my right hand, I willed the intricate crest of House Astaroth to glow faintly upon my palm. A second later, a sleek black crow materialized from the light, fluttering its wings and circling the ceiling of my room before dissolving into a faint wisp of white smoke.
Currently, my illusions were purely visual; the moment physical contact was made, they vanished like mist. I wondered if I could eventually condense demonic energy to give them tangible substance—essentially creating solid, interactable constructs akin to shadow clones.
'Wait... shadow clones?'
A brief shiver went down my spine. Moments like that kept catching me off guard, where fictional concepts and terms from Earth popped spontaneously into my head. It was momentarily disorienting, sometimes making me wonder where the old shut-in ended and the devil noble began. Yet, whenever that existential doubt crept in, I pushed it aside with firm conviction. While I possessed the vivid memories of a past life, I was fundamentally Alexander Astaroth now. My heritage, my future, and my identity belonged entirely to this world.
When it came to raw destructive potential, however, nothing compared to my inherited clan traits: Belial's 'Worthless' and Astaroth's 'Decay.'
I had taken Decay for a discreet test run out in an isolated corner of the courtyard, targeting an ornamental stone statue. The result was both awe-inspiring and terrifying. Even after I cut off the flow of demonic power, the entropy continued to spread autonomously for several seconds, reducing the sculpture and a sizable patch of surrounding stonework to fine grey dust. Mother had caught me in the act and delivered a surprisingly fierce scolding for ruining her beloved garden.
Recognizing the hazard of wielding an uncontrollable entropic force, I resolved to seal Decay away until I had proper mentorship. Since my father was utterly swamped catching up on work he had put off for a while, he personally reached out to the current clan head, Lord Astaroth, who graciously agreed to oversee my training in the near future.
Conversely, 'Worthless' proved far more intuitive to grasp. The Belial clan trait allowed the user to nullify incoming offensive or defensive magical phenomena, provided I understood the fundamental properties and composition of the technique being used. Negating standard elemental spells was almost second nature. It would be an absolute nightmare matchup against magic-centric devils who over-relied on singular gimmicks—like Rias Gremory and her Power of Destruction. Furthermore, because I could dissect the theoretical structure of holy and light magic, Worthless effectively neutralized an angel's primary advantage against me, virtually erasing a devil's greatest racial vulnerability.
Armed with these gifts, my ultimate trajectory became clear over the course of the week: I intended to ascend to the position of Satan, standing at the apex of the Underworld alongside my father. To achieve that, raw combat prowess alone wouldn't suffice; I needed formidable political standing, widespread prestige, and steadfast allies among the high-ranking nobility. Formal galas, rating game banquets, and political summits would provide ample opportunities to forge those ties.
There was, however, one catastrophic obstacle lurking within my own family: Diodora Astaroth.
In canon, Diodora's future descent into depravity, treason, and longtime collaboration with the Khaos Brigade not only led to his demise at the hands of Shalba Beelzebub, but it completely disgraced House Astaroth, effectively barring any member of our bloodline from ever holding a Satan seat again.
I had wondered whether Diodora had been born a despicable monster or if his environment warped him over time, so I decided to visit him personally. Just as Rias had once described, I found a deeply insecure, spoiled, and socially awkward child. Bitter and frustrated over failing to inherit the Astaroth clan trait, he frequently took out his anger by lashing out at the servant staff, while Lord and Lady Astaroth indulged his every whim out of pity and guilt.
When I first approached him, Diodora was extremely wary and resentful of my presence. But over the last several days, I made a conscious effort to drop by his quarters regularly. We played games, talked about trivial matters, and shared meals. Bit by bit, his hostile demeanor softened, and he genuinely seemed to brighten up whenever I visited. Beneath the prickly exterior, he was still just an insecure kid desperate for validation. While I couldn't see any immediate signs of the twisted madman he would become in the anime, I swore to keep a vigilant eye on him just in case.
I had even invited Diodora to join me in greeting the visiting heirs of House Gremory and House Sitri, but he immediately shrank back and turned me down. It would clearly take time for him to become more sociable.
*Sigh.*
' Well, there goes my brilliant plan of ditching him with the two girls and running off. '
On a brighter note, I also spent time with Latia Astaroth, a young girl from a prominent branch family. Initially timid and overly formal around the main house's prodigy, she gradually loosened up as we spent time together. Latia was sharp, polite, and remarkably level-headed. Remembering that she would eventually become the next heir who worked tirelessly to restore Clan Astaroth's honor after Diodora's downfall, I made sure to foster a genuine, comfortable friendship with her. Having someone of her caliber firmly in my corner would be invaluable down the road, and the two of us actually got along very well.
I spent the remainder of my final evening buried in historical archives, meticulously reviewing Underworld politics and the intricate fallout of the Great Devil Civil War until my eyes grew heavy. Tomorrow morning, the other Great Satans would arrive at the estate for their high-level summit, bringing their younger siblings—Rias Gremory and Sona Sitri—along with them.
Sliding beneath the silky sheets of my bed, I stared up at the vaulted ceiling and let out a weary groan.
"Ugh... I'm really not looking forward to tomorrow," I mumbled to myself before surrendering to sleep.