Looking at the devilish smile on Ren's face, Tanjiro could only stay silent and quickly run towards the foot of the mountain.
The mountain wasn't particularly high, only about two hundred meters, and the distance for two round trips wasn't excessively far—roughly seven kilometers. However, the terrain was steep and the mountain path was rugged, making it difficult to traverse.
But as long as Tanjiro could master Sun Breathing, these steep mountain paths would feel like flat ground to him. By then, running two round trips would be as simple as a short marathon.
It was just that Tanjiro had only just recovered from a serious illness, so making him do parkour back and forth on the mountain was indeed a bit hard on him.
But time waited for no one. Although the evil demons had been quiet recently, no one knew if Kibutsuji Muzan would make any new moves. Therefore, Ren could only cherish every minute and second to intensify Tanjiro's training.
While Tanjiro was jumping up and down the mountain path, Ren wasn't idle either. He was also training his swordsmanship. While improving his basic attributes, he was also working to thoroughly master the Thunder Combat Technique he had recently acquired.
He arrived at the mountain peak, looked at the protruding rock wall in front of him, and with a thought, a crest suddenly appeared on his forehead. His heart rate soared instantly!
"Thunder Combat Technique: Thunder God Heaven-Slaying Slash!"
In a split second, Ren slashed out. The speed was as fast as lightning; one couldn't even see an afterimage.
Bang!
A sword light resembling a lightning bolt flashed past, and the heavy Nichirin Sword in his hand smashed against the hard rock wall with overwhelming force, emitting a deafening roar.
This strike was earth-shattering and magnificent!
Even Tanjiro, who was sprinting at the foot of the mountain, heard the loud noise.
'What a loud sound. I can even hear it from here? Is Brother Ren training? It looks like I have to keep working hard too. Even if I can't surpass Brother Ren, I must at least be able to see his back!'
With this thought in mind, Tanjiro endured the physical fatigue and continued to sprint forward. During this time, he constantly adjusted his Sun Breathing, and the speed under his feet became faster and faster. He was practically flying, and the influence of the rugged mountain path on him became much smaller.
Ren didn't expect that his unintentional sword swing would encourage Tanjiro. He was simply swinging his sword and hacking continuously.
For a time, deafening roars rose and fell incessantly.
In the face of his violent attack power, the rock wall in front of him was smashed into a pitted mess, looking like a honeycomb briquette. He had forcibly chopped three meters off the entire mountain!
Looking at the ruined walls before him, Ren clutched his slightly aching heart, panting roughly as he muttered.
"Still not enough! I need to continue improving my physique. I must at least be able to adapt to the side effects brought by the Thunder Combat Technique..."
As he spoke, Ren opened his attribute panel.
[Ren]
[Strength: 260]
[Speed: 230]
[Constitution: 232]
[Five Senses: 170]
[Combat Techniques: Meteor, Whirlwind Dance, Dragon Dance, Thunder God Heaven-Slaying Slash]
...
After the battle with Kokushibo, Gyokko, and Hantengu, his basic attributes had improved immensely.
Strength increased by 8 points, Speed by 4 points, Constitution by 7 points, and Five Senses by a whopping 15 points.
After all, in order to dodge Kokushibo's attacks, his vision and hearing had been pushed to their limits, so it was no wonder his Five Senses attribute had increased so much!
Although his physique was already twenty times that of a normal person, it was obviously still not enough to withstand the heart overload caused by the Thunder Combat Technique. He had to continue exercising and improving his physique...
Five days passed in a flash. Over these five days, Ren constantly swung his sword and used the Thunder Combat Technique. The mountain peak rumbled constantly, as if the Thunder God had descended.
No one knew exactly how many times he had swung his sword. They only knew that the originally protruding mountain peak had been forcibly smashed into a large crater by him!
Despite this, Ren was still dissatisfied. With his current physique, once he used the Thunder Combat Technique, he could maintain it for at most three minutes, and definitely no more than five.
Once he exceeded three minutes, pain would start coming from his heart. After five minutes, the heart-wrenching pain would become unbearable!
The reason he could fight the three demons, including Kokushibo, last time was entirely because anger brought adrenaline, helping him break through his limits.
There was a saying on the internet in his past life: when the body reaches its limit, adrenaline will lead you to fight your way out.
Right now, his body wasn't secreting adrenaline, so he could only exercise his body bit by bit to enhance his strength.
It wasn't just Ren; Tanjiro hadn't relaxed his training these days either. Now he had mastered Sun Breathing, could run for long periods, and successfully ran two round trips around the back mountain within an hour.
And as Tanjiro successfully reached the standard, Ren also started the second phase of training for him.
Five hundred push-ups, five hundred sit-ups, five hundred squats, and a ten-kilometer long-distance run every day!
That's right, this was the famous Teacher Saitama training method. And aside from the long-distance run, Ren had multiplied the remaining three items by five for Tanjiro.
This was also to train his strength!
After all, strength is the foundation of attack power. Without absolute strength, one cannot cut the necks of evil demons; Kocho Shinobu knew this from deep experience.
Moreover, the stronger the evil demon, the harder their neck. At the level of the Twelve Kizuki, the hardness of their necks was comparable to steel.
Although the training volume was extremely arduous, out of trust in Ren, Tanjiro still worked hard to exercise, hoping that one day he could use his own strength to protect his family.
'Once the strength training is over, I can start teaching him sword swinging techniques to enhance his attack power.'
Looking at the hardworking Tanjiro, Ren smiled faintly and began his own training.
...
Inside the Infinity Castle.
While Ren and Tanjiro were training like wildfire, Muzan wasn't idle either. He was trying every method to create stronger evil demons.
"Lord Muzan, your subordinate has brought what you need!"
With a brilliant smile on his face, Doma knelt "obediently" in front of Muzan. Behind him were forty beautiful girls, looking as fair as flowers.
These girls were scared pale, their faces filled with fear. They never expected that the Cult Leader, who looked gentle and kind on the surface, turned out to be a legendary evil demon.
"Lord Muzan, these people are top-quality goods. How will you deal with them? Are you going to eat them?"
"Of course not! I'm going to conduct a little experiment!"
Ignoring Doma's disgusting expression, Muzan walked straight to a girl. With a thought, his finger suddenly elongated, and his sharp nail became as keen as a blade.
Pu!
He pierced the girl's shoulder in one move and poured his own blood into her.
Soon, amidst intense pain, the girl's eyes turned blood red, and her teeth began to grow. Without a doubt, the girl had been transformed into an evil demon by Muzan.
However, this wasn't over. Soon, python scales grew on the girl's body, her lower body turned into a thick snake tail, and sharp fangs grew in her mouth!
She evolved directly from a normal demon into a Heteromorphic Demon!
Seeing this scene, Muzan couldn't help but laugh out loud.
"Hahaha, that brat's blood is truly amazing. It can actually promote the evolution of evil demons. I merely injected a little blood into this woman, and she turned into such a powerful Heteromorphic Demon!"
"My experiment was a success. As long as I can devour him, I will definitely be able to overcome the weakness of sunlight and walk under the sun! Hahaha!"
[Reviews - Power St0nes - Comments are highly appreciated to keep me going.....(+50 chapters) patre0n.c0m/talecrafter]