"Clang—"
A crimson light, like a barrier, rose from the Magic Circle etched on the ground, enveloping Leo and Yukinoshita Yukino who stood within it.
Yukinoshita Yukino felt her vision gradually covered by the red light, but soon it dimmed, allowing her sight to return.
And when her vision returned, Leo and Yukinoshita Yukino were no longer in the Service Club room at Sobu High School, but had arrived in an incredibly spacious underground training room.
It was the training room located beneath Leo's estate.
"We really transferred in an instant..."
Yukinoshita Yukino looked at a Magic Circle on the ground, identical to the one in the Service Club room, and muttered softly.
"There's still some time before class, so before that, let me help you get familiar with your own power and situation." Leo was already used to such phenomena. He snapped his fingers, drawing Yukinoshita Yukino's attention, and said, "Do you remember the knowledge about Familiar Demons I gave you on the way to school?"
"Of course." As an honor student ranked first in her grade, Yukinoshita Yukino's memory was naturally excellent, especially in a situation closely related to herself. Her brain was fully active, and she said earnestly, "Including me, all Familiar Demons who have reincarnated as demons were reincarnated using a tool similar to a Western chess piece, right?"
"Yes, those are called devil chess pieces. They are reincarnation tools created by the current Demon King Beelzebub to save the dwindling demon population, and only High-Class Devils with noble titles are granted them." Leo nodded and said, "According to the classification of chess pieces, I am the 'King'. After being registered on the stone tablets in the lord's castles in the various territories of the Underworld or the Demon King's castle in the Demon King's territory, I received a total of fifteen devil chess pieces."
"These fifteen pieces are one 'Queen', two 'Rooks', two 'Bishops', two 'Knights', and eight 'Pawns'."
"After these fifteen pieces are granted to others, and they are reincarnated as demons, the Familiar Demon will acquire different characteristics depending on the piece they received."
Leo extended his hand, and a Magic Circle unfolded on it. From the Magic Circle flew out bright red chess pieces, which arranged themselves in front of Yukinoshita Yukino.
"The 'Rook' has astonishing attack power and tough defense, and can use an ability called Castling. Its value is equivalent to five Pawns."
"The 'Bishop' has the characteristic of magic power, suitable for Retainers who are skilled in using magic power. Its value is equivalent to three Pawns."
"The 'Knight' has the characteristic of speed, suitable for Retainers who are skilled in high-speed combat. Its value is also equivalent to three Pawns."
"And the 'Queen' piece has the highest value, equivalent to nine Pawns. It possesses the power of all the above pieces; whether it's attack power, defense, magic power, or speed, it is the strongest among all Retainers."
As Leo introduced each one, the pieces he described flew successively in front of Yukinoshita Yukino. Finally, eight pieces flew over together, their appearance identical.
"These are the last 'Pawn' pieces. Although their value is the lowest, their number is the largest. Their characteristic is promotion; they can be promoted to any of the above pieces on a field that the 'King' designates as enemy territory, possessing the abilities of the corresponding piece and changing freely. They are a variable whose presence may be low but absolutely cannot be ignored."
After Leo finished introducing all the devil chess pieces, Yukinoshita Yukino immediately understood.
"So... I'm your 'Bishop', right?"
Yukinoshita Yukino noticed that among the devil chess pieces Leo had shown, only one type was currently missing: the "Bishop."
The single "Queen" was still there, and all eight "Pawns" were accounted for, including the two "Rooks" and "Knights." Only one "Bishop" remained, and what this meant was clear at a glance.
"That's right." Leo put away all the devil chess pieces and said with a smile, "You are one of my 'Bishops'. Your characteristic is magic power. After reincarnating as a demon, your magic power has become quite strong, far exceeding that of ordinary low-ranking demons."
At this point, Leo looked at Yukinoshita Yukino with a somewhat satisfied expression.
After reincarnation using devil chess pieces, the quality of the Retainer is not fixed but determined by their individual potential.
For example, magic power. All demons possess magic power, even reincarnated Familiar Demons. However, some Retainers will have strong magic power after reincarnation, while others will have very weak magic power. This primarily depends on whether the reincarnated person themselves has talent in this area after becoming a demon.
One of the future famous Two Heavenly Dragons, the one known as the Red Dragon Emperor, had pitifully little magic power when he reincarnated as a demon, unable even to perform Magic Circle jumps. He could only ride his bicycle every night to find humans to distribute flyers to, which was quite undignified.
Yukinoshita Yukino, however, awakened a considerable amount of magic power after reincarnation, almost reaching Leo's level when he was ten years old.
It should be known that his magic power at the age of three was already among the best of Mid-level Demons, and after seven years of training, his magic power was even stronger, almost touching the limit of Mid-level Demons.
Yukinoshita Yukino possessed such strong magic power right from the start. While the enhancing factor of the 'Bishop' piece's characteristic certainly played a role, her own magic talent was definitely not low, in no way inferior to some pure-blooded demons, making her a definite potential stock.
She truly lived up to her role as a primary female lead in her original world; whether as a human or a demon, she was an absolute honor student.
With proper training, Yukinoshita Yukino would quickly become a qualified Mid-level Demon combatant, and one of the best among Mid-level Demons at that.
This was only considering her qualities as a demon.
Compared to the true power slumbering within Yukinoshita Yukino, her demonic power was almost negligible.
"Now, close your eyes and imagine the strongest thing you can think of in your mind."
Leo's purpose for this trip was to guide Yukinoshita Yukino to awaken the power slumbering within her.
Yukinoshita Yukino subconsciously obeyed her "master's" command and closed her eyes.
"The strongest thing... huh?"
Yukinoshita Yukino immediately thought of one person—Yukinoshita Haruno.
That was her older sister, and also the person she had always looked up to, the one she always wanted to surpass.
She was excellent, Yukinoshita Yukino had that confidence, but it depended on who she was being compared to.
Compared to her older sister, who was hailed as a perfect superhuman, she was far behind.
For many years, Yukinoshita Yukino had lived in the shadow of her excellent older sister, so her life was not particularly happy.
At home, just like at school, she experienced a similar sense of isolation because she was neither as beloved as her sister nor able to meet everyone's expectations. Although in the eyes of those around her, she was a well-behaved and sensible child, that also implied being cold and unlikable, which had always bound Yukinoshita Yukino.
Therefore, while Yukinoshita Yukino was confident, she was also insecure, believing herself to be merely a substitute for her sister, like a doll without a self, longing for change yet feeling lost about the future.
In such circumstances, even though Yukinoshita Yukino clearly knew that in practical terms, Leo and yesterday's Fallen Angel were stronger than Yukinoshita Haruno, when it came to the strongest thing, she still inevitably thought of her older sister.
This was the result of deeply ingrained subconsciousness, regardless of fact.
And in that instant, Yukinoshita Yukino's emotions fluctuated uncontrollably, causing the deeply hidden power within her to flow.
"Now, draw out that power."
At Leo's sudden voice, Yukinoshita Yukino almost held her breath, reflexively complying.
"Boom!"
Suddenly, a roar echoed through the air.
The temperature in the training room plummeted, allowing icy cold winds to rage, stirring up gusts of snow.
Yukinoshita Yukino's clothes violently fluttered, her eyes tightly shut, but behind her, a figure appeared out of thin air.
It was a humanoid monster, about three meters tall, entirely made of ice, shaped like it was wearing a gown, with four slender arms, no mouth or nose on its face, six eyes on its left cheek, and something resembling forward-protruding thorns on its right cheek.
"W-what is this?"
Opening her eyes, Yukinoshita Yukino saw the ice princess standing behind her and couldn't help but be startled.
Leo's voice came at just the right moment, reaching her ears.
"This is the true form of the god-slaying tool residing within you."
Leo came to Yukinoshita Yukino's side, gazing at the three-meter-tall ice princess, a slow smile spreading across his lips.
"god-slaying tools vary in strength; strong ones can allow the host to exert power comparable to gods and Demon Kings, while weak ones can only cause some influence on daily life."
"Most god-slaying tools have the latter function, capable of affecting at most human society, unable to influence transcendent beings like us."
"But among god-slaying tools, there is a small portion powerful enough to threaten beings like us, and an extremely rare portion possesses the power to destroy gods and Demon Kings."
Leo's eyes sparkled as he looked at the ice princess.
"Those are the highest-grade god-slaying tools, terrifying powers whose movements are closely monitored by Heaven and the Child of God Monitors due to their strength and danger."
"Currently, there are only thirteen such terrifying powers, each of which could potentially disrupt the balance between factions."
"We call them—'god-slaying tools'."
The god-slaying tool held by Yukinoshita Yukino was, like Blazing Heaven Thunder Prison, something renowned as a god-slaying tool.
"'Absolute Demise'—the eleventh-ranked god-slaying tool, a legendary independent materialized god-slaying tool capable of freezing everything and creating a world of ice crystals."
In the original work, this god-slaying tool belonged to a magician named Lavinia Reni.
But in this world, Yukinoshita Yukino had become its master.