After listening to the system's explanation, Horigaku felt conflicted:
"This...My personality isn't as bad as in the original story, and I didn't cause Himejima to be imprisoned. That's a good thing, so it's a positive butterfly effect. I understand that.
"But me learning the First Form of Thunder Breathing is also a good thing! How could it trigger a negative butterfly effect!?"
The system's calm electronic voice sounded in his mind:
"The butterfly effect involves causality and spacetime; it is elusive and unpredictable. The probability of both positive and negative butterfly effects occurring is fifty percent each."
"Fine, so what exactly is the negative butterfly effect I unintentionally triggered this time?"
Ding!
The host learning the First Form of Thunder Breathing and breaking fate has triggered the following negative butterfly effect: The protagonists of this world, Kamado Tanjiro and Kamado Nezuko, are about to die!!!
"What did you say!?!"
Horigaku jumped up in agitation, his mind in turmoil:
"My future brother-in-law and future wife are going to die!? Just because I learned the First Form!? If I had known, I wouldn't have learned it! What should I do now!?"
Horigaku wailed in despair in the snow, then quickly forced himself to calm down and think rapidly.
But after thinking for a long time, he couldn't come up with a solution:
"It's all because I wasn't careful when watching the anime; I don't even know exactly where the Kamado family lives. I can't find them! How can I save them!? My wife! My brother-in-law!
"What should I do!? What should I do!?
"Mount Kumotori! The Kamado siblings' destination should be Mount Kumotori! I should be able to find them if I head in the direction of Mount Kumotori! If I ask the old man, he definitely knows where Mount Kumotori is!
"And there's Giyu Tomioka! By this time, Tomioka should have already met the Kamado siblings. Asking Tomioka to find them might work!
"Dammit! The problem is... will there be enough time!? System, oh system, what do you mean by 'about to die'? How soon is 'about'!?
"Wait! System! Aren't you the Butterfly Effect Control System? You must have a way!"
Perhaps it was Horigaku's imagination, but the system's electronic voice in his mind seemed somewhat helpless:
Ding! Please do not overly agitate yourself, host. One of the system's responsibilities is to help the host resolve negative butterfly effects.
"Then hurry up!"
*Ding! The system is issuing a task:
Please resolve the negative butterfly effect: the death of the Kamado siblings!
The system has a pathfinding function that can assist the host in locating the Kamado siblings.
According to system detection, the host's current strength, if sufficiently cautious, is enough to counter the danger the Kamado siblings are about to face.
Friendly reminder: There are 24 hours left until the Kamado siblings' time of death. Please travel promptly.
Task success reward: Advanced technique of Thunder Breathing, First Form: Thunderclap and Flash.
Task failure penalty: Kamado Tanjiro and Kamado Nezuko die. The world loses its main characters. Fate undergoes significant changes, and the butterfly effect further collapses!*
Looking at the task details, Horigaku was momentarily stunned.
So... that's how it is.
I trigger butterfly effects. The system doesn't intervene in positive ones, but for negative butterfly effects, the system issues tasks for me to resolve personally, while the system's rewards enhance my strength.
Killing two birds with one stone!
As Horigaku was lost in stunned surprise, a 24-hour countdown appeared in the upper right corner of his vision.
Without a doubt, this was the system's time reminder!
"System, well done! I'm setting off now!"
Without another word, Horigaku sprinted back home, straight to Kuwajima's house on Peach Mountain!
He roughly pushed open the door,almost tearing it off its hinges, and rushed inside to start packing. Kuwajima inside looked utterly bewildered:
"Brat, what are you doing?"
Horigaku kept his head down, packing rapidly:
"Old man, this coat looks warm, I'm borrowing it! Your spare Nichirin Blade is also borrowing it! And these rice balls will serve as rations for the journey..."
Veins bulged on Kuwajima's forehead:
"Brat, what exactly are you planning to do!?"
Once packed, Horigaku dashed out, quickly descending the mountain.
Kuwajima stood at the doorway, shouting angrily:
"What's going on!? Where are you going, kid!? When will you be back!?"
From afar, obscured by branches, Horigaku's distant voice echoed back:
"I'm going to find my future wife and future brother-in-law! Don't worry, I'll be back in a few days..."
Leaning on the doorframe, the old man's eyes turned into dots:
"Future wife and future brother-in-law? How come I didn't know anything about this? Were his previous trips down the mountain for this reason too?"
As he thought about it, Kuwajima began to indulge in pleasant fantasies, petals seeming to bloom around him, and the art style turned cute:
"That's wonderful, the brat has reached the age to consider his lifelong matters. I wonder which family's girl it is? Is she pretty? Is she virtuous? Is she a good match for my brat?"
Meanwhile, Horigaku, having run down the mountain, found the road and, following the system's pathfinding prompts, hurried on his way.
As he ran, he thought to himself:
I must make it in time, I will definitely make it in time!
The system wouldn't issue a task I couldn't complete!
As long as I maintain my breathing rhythm and use Thunder Breathing properly, I can make my stamina last longer and my speed faster.
I might even incidentally learn Total Concentration Breathing.
Nezuko, my future wife, you must be safe!
Tanjiro, although it's somewhat incidental, you can't be in trouble either.
If something happens to you, the plot will be messed up, and my transmigrator's foreknowledge advantage will be diminished!
And so, Horigaku traveled non-stop for twenty-four hours.
When hungry, he casually ate a rice ball; when thirsty, he drank some stream water; when tired, he rested only if absolutely necessary; when sleepy... someone on a urgent journey doesn't get sleepy!
Just like that, a day and night passed, and the 24-hour countdown was nearing its end.
So, what exactly is the lethal danger the Kamado siblings are about to face?
Logically, after the Kamado siblings' initial tragedy and on their journey to Mount borrowing, apart from encountering the Demon at the very end, they shouldn't have met any other demons on their way.
However, due to the occurrence of the negative butterfly effect, this time, the Kamado siblings unfortunately encountered another demon on their journey, and one with a special ability at that!
"Nezuko!" Tanjiro shouted hoarsely for his sister.
The brother who wanted to protect his sister now found the situation completely reversed—it had become the sister protecting him!
During their journey, the siblings were terribly unlucky to encounter a demon.
Tanjiro was no match for this demon.
Fortunately, Nezuko, who had already turned into a demon, possessed considerable combat power.
She bravely rushed out to protect her brother.
Clutching his bleeding arm, watching the demon trading blows with Nezuko, Tanjiro stood helplessly with his axe, panicked and at a loss.
In terms of pure strength and speed, this demon wasn't particularly outstanding.
But this demon had a special ability that had caused Tanjiro's injury and put him at a disadvantage!
Staring fixedly at the demon, Tanjiro noticed the enemy about to open its mouth and quickly shouted a warning to his sister:
"Be careful!"
The demon opened its mouth wide and actually shot out the four fangs from within! They flew towards Nezuko like four shuriken!
Although warned, Nezuko dodged, but one fang still struck her back!