Muzan lowered his head, silent, though a trace of defiance flickered in his eyes.
"That is because you rely too much on Blood Demon Arts," Sol Mirek said, his voice carrying through the ruined courtyard. "Real power comes from the body itself. Yoriichi Tsugikuni had no Blood Demon Art, yet he nearly killed you. That is the difference."
Kokushibo's body trembled at those words.
Sol glanced at him. "Not satisfied? Your brother had greater talent, that much is true. But if you had focused on your own potential instead of chasing power the wrong way, you would not be this far behind."
Kokushibo dropped to his knees, all six eyes filled with shock. "Your lesson is understood."
"Good," Sol replied lightly. "We continue tomorrow. If you want the Blue Spider Lily, then prove you are worth it."
Muzan pressed his forehead to the ground, his voice trembling. "You are right. We will push ourselves further."
Sol gave a small nod, his gaze sweeping across the Upper Ranks. "Same time tomorrow. Do not disappoint me."
With that, he turned and walked away, his figure fading into the morning light.
Only after he disappeared did Muzan slowly lift his head. Cold sweat covered his pale face. His eyes shifted toward the other demons, something ruthless surfacing within them.
"You all heard him," Muzan said quietly.
"From today onward, every one of you will strengthen yourselves."
Kokushibo's six eyes opened wide. "He is right. We have relied too heavily on Blood Demon Arts."
"Enough," Muzan snapped. "What matters now is surviving tomorrow."
Doma emerged from a pool of blood, his usual smile still in place. "How frightening, truly. Still, being guided like this is… an honor."
Gyutaro held his injured sister close, his voice rough. "Do we really trust him? What if he never gives us the Blue Spider Lily?"
"Silence," Muzan hissed, his nails digging into his palm.
"This is our only chance."
Meanwhile, Sol walked through the quiet morning streets, sunlight resting on his shoulders. People glanced at him curiously as he passed.
A faint smile lingered on his lips.
"That fear in their eyes," he muttered, amused. "Not bad."
He stretched slightly as he walked. "At least they will not try anything stupid."
By the time he returned to the Demon Slayer Corps headquarters, Kagaya Ubuyashiki was already seated in the courtyard.
"You are back," Kagaya said gently.
"Yeah," Sol replied, sitting down casually. "They are behaving well."
Kagaya's fingers twitched slightly. "How is their progress?"
Sol poured himself some tea. "Better than yesterday. They last a little longer now."
Kagaya nodded, thoughtful. "I have a request, if you are willing."
Sol took a sip. "Go on."
"Could you also guide the Hashira? They, too, must grow stronger."
Sol set the cup down and glanced toward the other side of the courtyard, where the Hashira were training.
"They are too weak," he said bluntly. "They would not survive my kind of training."
A sharp voice cut in.
"What did you just say?"
Sanemi Shinazugawa strode forward, his expression fierce.
Sol looked at him, unfazed. "Exactly what you heard."
Sanemi clenched his fists. "Do not look down on us. We may not be as strong as you, but we are the Hashira. We will grow stronger. One day, we will stand at your level, and we will wipe out every demon."
Sol stood up, a faint grin forming.
"Then prove it."
Sanemi did not hesitate. He drew his Nichirin blade.
"Wind Breathing, First Form: Dust Whirlwind Cutter!"
A sharp gale surged forward, slicing toward Sol.
Sol did not move. Just before the blade reached him, he shifted slightly. His hand moved like a blade, tapping Sanemi lightly in the abdomen.
A heavy impact followed.
Sanemi was sent flying, crashing into the wall. His eyes widened in disbelief.
"How…"
The other Hashira froze, shock clear on their faces.
Shinobu watched quietly, her fan moving again. "The gap is… overwhelming."
Mitsuri rushed to Sanemi's side. "Are you okay?"
Sanemi pushed himself up, teeth clenched. "Again."
Sol shook his head. "No point. You cannot even make me break a sweat."
Kagaya sighed softly. "He is right. We are lacking."
Sol stretched his arms slightly, then spoke again.
"If you truly want to get stronger, I can give you advice."
Every Hashira turned their attention to him.
"First," Sol said, "drop the obsession with flashy techniques."
Uzui raised an eyebrow. "Flashy techniques?"
"Strength starts with the basics," Sol continued. "Ten thousand sword swings a day. Five thousand squats. Five thousand push-ups. Run one hundred kilometers."
Mitsuri blinked. "That sounds impossible…"
Sol shrugged. "That is only the beginning. If you cannot handle that, forget about getting stronger."
Shinobu tilted her head slightly. "So you mean we should return to the fundamentals?"
Sol glanced at her with mild approval. "Exactly. You focus too much on technique and forget what actually matters."
Kagaya nodded. "Very well. From today onward, the Hashira will train as you suggested."
Sanemi clenched his fists again. "It is just training. That is nothing."
Sol smirked. "We will see if you still feel that way tomorrow."
Night fell once more.
As promised, Sol returned to Muzan's mansion.
This time, Muzan and the Upper Ranks were already lined up, waiting in silence.
"You are early," Sol said, slightly amused.
Muzan bowed. "We are prepared."
Sol studied them briefly. Their presence had improved.
"Not bad," he said. "You actually tried."
A flicker of pride crossed Muzan's face. "Your guidance is effective."
Sol waved a hand. "Less talking. Show me."
Without warning, Kokushibo moved.
"Moon Breathing, Tenth Form: Drilling Slashes, Moonbow!"
A powerful slash cut through the air.
At the same time, Akaza attacked from the side.
"Destructive Kill: Annihilation Style!"
Sol's eyes lit up slightly. "Better."
He did not dodge. Every attack struck him directly, yet his body remained unmoved.
Muzan watched, his expression tightening. "Even now… it is hard to believe."
Sol stood calmly amidst the storm of attacks.
"Keep going," he said. "Show me your limits."
The battle continued deep into the night.
By the time dawn approached, the result was unchanged.
Muzan and the Upper Ranks lay scattered across the ground, reduced to broken flesh and blood once again, unable to resist.