Chapter 11: Karma

"Sakura, I decided to accept the Matou's adoption request."

It suddenly happened. Sakura didn't expect that after being called by her father while she was playing with her sister, she would receive this news—a very bad one.

"Both you and Rin possess outstanding talent as magi."

Talent. That's what she has. Both sisters have the same amount of magic circuits. Rin has the five-element affinity while Sakura has the Imaginary Numbers, a rare affinity to access the imaginary number space.

"This is for your own good."

Sadly, every magus family can only have one heir in the end. For the two sisters to not have a conflict, Tohsaka Tokiomi chose the best decision to adopt Sakura to another magus family. In this case, the Matou Family whom they know for 500 years.

Though, is it really the "best" decision?

*****

'W-what's happening?'

"Don't be afraid, little Sakura."

Zouken Matou said so with a cynical tone. His chuckles made it even more ominous.

Boom-!

Just as she was about to be pushed to that pit of hell, the metallic door sealing this hell flew all the way to the other side of the basement. The metallic door implanted itself into the wall very deeply as a result of "too much force" being applied to it.

"Tsk. Tsk. I blame Tohsaka Tokiomi for all this."

A soft yet firm voice resounded in this enclosed basement, surprising Sakura. As Zouken looked toward the source of that voice, he saw a young boy wearing a huge black robe.

His face can't be seen very clearly due to the darkness, but he was sure that the intruder is very young. Still, this did not prevent his cunning side from making plans.

"Who are you?" He asked with a calm yet rough tone.

"Me? I'm just a passing-by magus who decided to contribute to society."

Zouken readied the worms inside this basement, as well as the thousands of bugs that he kept here. He is very vigilant as he sensed the bounded fields outside were broken by the intruder alone.

Drawing the first attack, he sent out a large wave of blade wing worms toward the intruder.

"Turbulence Wind."

A wind wall consisting of sharp wind suddenly appeared out of nowhere, cutting all the worms that got close to it into pieces. Then, he followed it up with <Ring of Fire>, a flame mage craft.

The intruder sent a batch of turbulence wind at Zouken, cutting him into pieces.

Though, it wasn't effective as he is seen reforming in the worm pit after that attack. The intruder hurriedly went to the staircase and grabbed Sakura in his left hand.

Seeing this, Zouken cynically said, "Only this? You'll die if you keep it up."

"We'll see about that."

Shiro used the same attack again, the Light of Judgement. Magic circles appeared as light rays were summoned out of it. Each light ray pierced through many worms and burned them with its high temperature, yet it was proven useless.

Zouken sent out another batch of bugs again as retaliation. Only, their effect is unknown as these ones are not shown on the wiki that Shiro had read before.

"Heaven's Protection."

Another batch of magic circles appeared before forming a rainbow dome, isolating him and Sakura from the outside world. The bugs tried to break through but to no avail.

Shiro cleaned up these bugs once again using his flame magecraft. In doing so, he saw hundreds of prompts pop up, which made him disable them first as they are distracting.

"I'm an immortal, you can't kill me."

"Is that so?" He replied as he knew that this is one of Zouken's cunning tricks, making his opponents lose morale in front of his seemingly-immortal body.

Shiro disabled the barrier and went upstairs to have higher ground. This time, he kept sending Light Spears as well as some mental power attacks to the bugs who are coming after him, so as to conserve his mana.

From the start until now, he used up more than 35% of it already. If not for him repeatedly using his reserves on his Mana circuits, it might be even lesser.

"Hello, Sakura-chan."

"Who are you?" The girl asked while trembling.

He saw her eyes full of tears. Right now, she is still shivering due to the traumatic experience she had earlier.

"I'm with Shinji-kun, don't worry."

"Onii-sama?"

"Shinji? I did not know that he would know a strong magus."

"Oops. Did you hear it? I expected that you're only a rotting old bastard, but it looks like you still have some of your senses, huh."

Shiro launched the third Light of Judgement to the worm pit yet again. He was now cornered into the entrance, but he didn't care and continued buying time in this basement.

"Of course, it is still sharp. Sharp enough to kill an intruder like you." Zouken replied.

Shiro didn't mind it as he saw the messages from Shinji 5 minutes ago.

*****

[Private] Shinji: "It's not in the living room either."

Shinji ran through the entire mansion with a tense expression.

"It's not in the study, living room, bedroom, and courtyard..! Huff..."

Right now, he is running in the direction of their garden. He tried looking for the main worm earlier, but he still couldn't find it.

Earlier on, he used an application of aura, which is to make them into thin strings and sense their surroundings with them. Since both Shiro and Shinji guessed that his bedroom and study is more likely to be filled with traps, they used this way of checking them instead.

Just a small life force. That's all he needed to find. Once he found it, he would've used the Spell Card that Shiro gave him before.

"Another bounded field? Damn it!"

A blazing blue flame covered his fist as he pinched the spell card, effectively breaking the bounded field with a single punch.

As he entered the garden, he felt that the mana concentration here is higher. It is only natural as Zouken would place these plants filled with mana in mana-rich places.

This way, they would grow and be preserved better.

Shinji created such aura threads again as he tried to detect the life force in this place, only to fail as these places are full of such plants.

"The plants are messing with my senses. What should I do..?"

He knew that every second he spends here means more danger to Shiro, so when he thought of a direct solution to this problem, he never hesitated one bit.

He pinched the spell card again, this time applying it to the plants. They were burned by the blazing blue flames in no time.

As the plants got cleared up, he could sense the life force better. Shinji tried looking for it again until he sensed a very faint signal of life underground.

"Underground!"

Now, he wondered how to reach that said signal. He's just an eight-year-old child who's also a 1st Rank Aura Knight. Even if he could stomp on the ground to dig, it would only be more than half a meter deep.

"The last usage..!"

Shinji punched through the soil hard, causing his fist to sink. There, he unfolded his fist before pinching the spell card one last time. Blazing blue flames erupted from within the soil, making them collapse.

Cracks started appearing on the ground before they collapsed and made a deep pit.

Sensing the signal once more, Shinji got into position and punched out the soil, making the soil hit become craters. His fist went deeper until...

"Reach it!"

He used up the majority of his aura left and strengthened his fist again. As he used his remaining power this time, it caused a deeper impact on the soil.

It was then.

"Kuaa!"

Shinji heard a weird screaming sound coming from underneath his fist. Removing it, he saw a strange bug that was squashed to pieces by the impact before.

[Private] Shiro: "Good job."

Seeing this, he collapsed instantly due to fatigue.

*****

Shiro typed mentally before focusing his attention again on the now-screaming Zouken Matou. As for Sakura, he already asked her to leave through the entrance since he lost the enhancement that the character card had brought to him.

Meaning, he fought against Zouken purely with magecraft left. He used Gradation Air to project different kinds of rifles as he shot the bugs while using flame magecraft.

With these, his mana reserves dropped faster. He thought that he had to resort to using the entirety of his mental power if even his B-Rank Mana couldn't take it, but he saw Zouken suddenly scream.

"Heh. Seems like your karmic retribution has arrived." He said. "Your actions in that route ended up giving away your deepest secret."

Turns out, the information that they leveraged into is Zouken's actions during the Heaven's Feel route, in which he implanted his "Main Worm" in Sakura's heart to stay immortal. However, Kotomine Kirei's action served as his greatest counter, leading him to be purified by the rites of baptism even with his main worm intact.

Still, this gave the members many ways to kill Zouken efficiently, with killing his main worm being the most efficient one.

"Go burn in the deepest pits of hell."

Using the strongest flame magecraft as well as the mental power that he can use right now, he burned the rest of the blood worms, killing Zouken Matou in the truest sense.

[Quest Complete. Rewards settlement...]

[+30,000 Soul Points]

[+5,000 Soul Points]

[+1 Acquired Mastery Chance]

[+1 Elemental Affinity (Fire)]

[+1 Elemental Affinity (Wind)]

[+1 Latent Potential Accessor]

The moment the prompts showed up is the moment that marks the end of Zouken Matou's life.