East Blue, Shimotsuki Village Isshin Dojo.
Under the scorching sun, near the well at the Isshin Dojo, Kozaburo sat on a bench. In his right hand was Wado Ichimonji, and in his left, a long, straight, flaming red sword. With his bare hands, he rubbed the blade, perfecting its shape. The 1.4-meter-long blade had a snow-white edge and a flaming red spine, with fire patterns on the blade.
Sephiroth squatted down, watching Kozaburo, who was concentrating intently. He simply waited in silence.
After a long time, Kozaburo stopped, sheathed the sword in its black scabbard, and handed it to Sephiroth.
"After three years, your sword is finally finished! Take it. I hope you can make it famous and recognized by the world, and then officially have it included in the list of the 12 Saijo O Wazamono swords," Kozaburo said.
Sephiroth smiled. "Don't worry! I'll do it. Now, I'm going to test the sword! Do you want to see?"
"Of course!" Kozaburo replied, his eyes sparkling.
Kuina, who happened to be passing by with her bamboo sword, immediately ran over. "I want to see too!" she said, full of curiosity.
"Alright!" Sephiroth nodded, clipped the sword to his waist, then took out his other sword. He opened a Spatial Door to a sandy beach. The three of them entered, and in an instant, they arrived at a beach ten kilometers away.
Sephiroth sheathed his sword, walked to a coconut tree, then pulled out the flaming red sword, the Underworld Sword. He held it, feeling a slight heat from it.
Swoosh!
With a single swing, the coconut tree in front of him was instantly cut and fell on the sand, with a scorched mark on the cut side.
"Not bad! The sword is very sharp, and it can unleash fire attacks," Sephiroth said, his eyes gleaming with joy. He realized that this Underworld Sword with its fire attribute could enhance the adaptation of his Mera-Mera no Mi, allowing him to exert the full power of the Devil Fruit.
Kozaburo took a puff on his cigarette, sighed, and said proudly, "Of course! This Underworld Flame Sword is the greatest masterpiece of my life! Not only does it have a fire attack, but it can also absorb Armament Haki. In terms of quality and characteristics, it's a top-tier sword! I never thought I could forge a famous sword stronger than Shusui."
After testing the sword's sharpness, Sephiroth turned, looking at the boundless blue ocean in the distance, with the new sword in hand and burning ambition.
As Sephiroth took a deep breath, a wave of pitch-black Armament Haki began to spread from his right arm, quickly enveloping the Underworld Flame Sword until the entire blade turned jet black. The sword seemed to absorb darkness and power, radiating a terrifying aura.
Seeing this sight, Kozaburo, who understood his intention, immediately pulled Kuina a few steps away. The swordsmith stood in the distance, watching with eyes full of anticipation.
SWOOSH!
Sephiroth swung the Underworld Sword with full force, cleaving it vertically. A flash of fiery red sword energy streaked through the air, tearing the space in front of him. The powerful, burning shockwave immediately created a large trench on the sandy beach, splitting the sand until it continued to spread into the ocean, out of sight.
After a moment, the split seawater came back together, and the heat from the burning sword energy caused the surface of the sea to evaporate, creating a thick plume of white smoke. Soon, several large fish floated to the surface, their bodies split and charred. A faint scent of grilled meat wafted through the air.
Kuina's mouth opened, her eyes wide with wonder as she stared at the ocean that had reconnected. "Whoa! He... he even split the sky!?"
Kozaburo, with a dry tobacco stick in his mouth, looked up. In the sky above, a large crack suddenly appeared in the clouds, as if the sky itself had been torn by the sword's slash.
Kuina ran closer to Sephiroth, who had already sheathed his sword. "Sephiroth, your technique is amazing! Can you teach me?" Her eyes sparkled with hope.
Sephiroth chuckled. This is just a basic slash with full power, he thought. However, he gently patted Kuina's head. "Yes! Later, when Kuina grows bigger and stronger, I'll teach you everything I know."
After the "test," Sephiroth initially asked Kozaburo to continue forging several more top-tier swords for him. However, the legendary swordsmith refused. Kozaburo said that he needed to calm down and find inspiration for several years before forging another famous sword.
Having no other choice, Sephiroth finally gave up.
He then returned to the Baldo Kingdom, where Jin would help him fuse the Underworld Sword with his Mera-Mera no Mi.