At the heart of the Akirama family's legacy lies a unique and very powerful ability. In the original story, when Enrico saw it for the first time, he found it extremely strong even with its limitations. In the story, the name was "Shinketsu no Musubi." This ancestral technique, inherited exclusively by the direct descendants of the Akirama bloodline, was what sustained the family's magical and political supremacy for centuries—even when Tsuyokuni faced times of decline.
The essence of this ability lies in the formation of a spiritual and magical bond between two individuals called Ketsumei—the destined—and Musubinin. The Ketsumei is the one outside the Akirama family who is chosen as the "core" of the bond. The Musubinin is the member of the Akirama family who connects to them. After the bond is formed, the Musubinin begins to reflect the magical development and abilities of the Ketsumei, gaining access to a personal version, adapted to their own body and lineage, of all the power and magical talent of the destined one.
The process takes place through a specific ritual, passed down only to the eldest members of the Akirama house. When the ritual is completed, the Musubinin immediately receives a partial mirroring of the current magical circle of the Ketsumei, adjusted to the proportion of their own talents. For example, if the Ketsumei possesses magma magic in the first Circle with 80% mastery, and the Musubinin, even with a different affinity and still at Circle Zero with only 50%, they immediately rise to Circle One with 80% efficiency, respecting the relationship between the two.
Moreover, the Musubinin's future progression will follow in proportion to the Ketsumei. If the destined continues to evolve and acquire new spells or magical abilities, the Musubinin will also receive them—not the same spells, but they will develop parallel abilities to their own magic. Example if the Ketsumei develops magma magic and later an ice magic—even if it's a foolish combination since they're opposites—the Musubinin might awaken a magic opposite to their own.
Even so, "Shinketsu no Musubi" is not without limitations and is often compared to a double-edged sword. The first issue is that the difference in potential between the Musubinin and the Ketsumei can cause growth collapse. If the Musubinin has greater magical potential or evolves faster than the Ketsumei, this can stall the progression of the bond, stagnating the Musubinin's growth. Only the Ketsumei having greater potential avoids this risk—unless the Musubinin's potential is far lower.
The second problem is their age, which directly influences the strength of the connection. The closer in age the Ketsumei and Musubinin are, the greater the synchrony and speed with which the bond adapts. However, if the Ketsumei is much older and the Musubinin is still in early stages of growth, the bond may form, but initial gains will be nearly null. For this reason, it is strictly forbidden for adult Ketsumei to bond with young members of the Akirama family. Only Musubinin may bond with someone younger since this limitation is lesser—but who in the Akirama family would form a bond with someone younger, knowing that the more a mage grows and evolves, the further behind the younger ones are left? Only geniuses could break this logic.
And lastly, each member of the Akirama family can form only one Shinketsu no Musubi bond in their entire life, requiring wisdom in choosing their Ketsumei. This fact has, in the past, caused many internal disputes within the family—children choosing based on political interests, others trying to predict who the next prodigy would be, and some making the wrong choice and remaining stagnant for life.
Renzou's own rise as the Ketsumei of three Akirama wives was the result of hasty political decisions, driven by fear and a desire to strengthen themselves through a ninth Circle mage. The three women were of similar age, with a three-year difference from him, and the result was two of the wives only reached the seventh Circle, and the most talented—the first wife—reached the Eighth Circle with great effort, making the most of the bond and her own talent.
It was considered a moderate success but still a positive one. That's because, before Renzou's arrival to the family, no descendant had reached the Eighth Circle in the past twenty years. The Akirama bloodline, once feared and influential, had been in a long period of weakening since the death of the father of the three wives—a legendary Eighth Circle mage who took with him the prestige of the previous generation and could have reached the ninth Circle had he not died.
"Shinketsu no Musubi" was, for a long time, the pillar of the Akirama's supremacy. For generations, the family sought individuals with extraordinary talents—heroes, war geniuses, tribal leaders—and strategically bonded them with their descendants. It was a continuous cycle of power.
But political negligence and the fall of the empire made them retreat—until Renzou appeared.
Now everyone thought the same thing. With Enrico standing before them, and having chosen the family member with the lowest potential—who might hinder his own development—they couldn't believe it. Seeing the expectation in Renzou's eyes, even Rina, who had thought he was weak at first, began to suspect he might be a new prodigy.
"Are you sure?"
Renzou truly didn't understand Enrico. For Renzou, even if Enrico wasn't in Class S, he had shown great intelligence, could see the future, was in the same Circle as his daughter Rina, and even though he hadn't reached the highest class at Astrong, he was only one level below and the strongest in Class A—which meant he must have great potential. So he was filled with doubt—had Enrico seen something in the future?
"Yes sir, I'm sure."
Renzou nodded and asked Yumeha to come forward. She walked slowly and hesitantly, with a small hope in her eyes that maybe this wasn't a dream—after being looked down upon even by servants, citizens, and her brother, who had low potential but still more than hers.
No one seemed to care about her. She trained constantly but still hadn't reached a one Circle or discovered what magic she was compatible with. She was becoming desperate—considering even making a pact with demons. But now, if this boy—whom her father seemed to see as having great potential—had chosen her, maybe she could evolve. She knew her father and knew he wouldn't allow anyone in the family to form a bond with someone without potential, even if that person had saved his life.
"So how do we form the bond?"
Enrico looked at her, then at Renzou expectantly, and everyone in that room still didn't understand.