On the main training grounds, the Hashira's hellish special training continued.
Meanwhile, in a secluded clearing in the Butterfly Mansion's backyard, another special "remedial class" quietly began.
With a pop and a puff of white smoke, a figure identical to Sasuke appeared before Tanjiro, Zenitsu, Inosuke, and Kanao.
It was a Shadow Clone.
"M-Mr. Sasuke split in two?!" Zenitsu screamed in fright.
"Ooh! What kind of sorcery is this? Amazing!" Inosuke excitedly circled the Shadow Clone, trying to find a flaw.
Though Tanjiro and Kanao were equally shocked, they quickly calmed down.
Sasuke's Shadow Clone ignored their commotion and got straight to the point. "Starting today, besides your regular Breathing Style training, you'll undertake a new kind of training."
He pointed at his own body.
"Your Breathing Styles use special breathing techniques to force as much oxygen as possible into your lungs, allowing you to unleash strength beyond an ordinary person's for a short time. But that strength has limits, and it places an enormous burden on your bodies."
"My power comes from a different source."
The Shadow Clone extended his hand, and a ball of blue energy slowly gathered in his palm, flickering like a flame.
"I call it 'chakra.'"
The four gathered around curiously. They could sense the astonishing power contained in that ball of energy.
"Chakra is a form of energy refined by combining the physical energy of the human body's 130 trillion cells with the spiritual energy developed through training and accumulated experience. Simply put, it's a combination of body and spirit."
"It works along similar lines to your Breathing Styles, but it's more systematic and more powerful."
Sasuke's Shadow Clone explained concisely, "Today's lesson is to let you begin sensing the existence of chakra and learn the most basic method of controlling it."
He pointed