Law and the others had stayed in the Slu Tribe's settlement for over two years. Most of their time was spent on busy training, and they had joined the Slu Tribe on hunting trips multiple times, but never ventured too far.
This time, armed with much information provided by the Slu Tribesmen, they headed deeper into the underground world, ensuring they wouldn't wander lost.
So, the direction was correct, but trouble and danger arrived nonetheless.
The nature of the underground world was similar to the surface: threats near the coastline were always lower than those inland. The same applied underground… the closer to the earth's core, the more dangers one would encounter.
Those dangers could be strange creatures and strange phenomena.
This time, the trouble Law encountered was still the Bone Race, but not in a group… just one person and one horse.
In terms of appearance, calling it one person and one horse wasn't inaccurate, just several times larger. But on closer look, it could also be seen as a minotaur and a horse.
A bull riding a horse.
The horse was a Bone Nightmare, the bull a Bone Minotaur.
Both were tall and sturdy, their bodies entirely made of white bone. Even their eye sockets were empty, showing nothing. If not for the prickling sensation of being watched, one might think they had no vision.
The Bone Race was a strange existence. Among them were various types of biological forms, including humans.
Regardless of intelligence, their physical structure was strange: more bone than muscle. The higher up the symbolic pyramid of grade, the more bone and less muscle they had, even lacking blood and eyes.
How did such beings come into existence?
Once you had time to ponder this, it inevitably brought to mind the Dark Sonata, the solo piano version.
That tune's ability could strip living beings of flesh and blood, leaving only skeletons yet retaining their souls, allowing them to continue existing like a false immortality.
Law had once encountered that memory. The skeletons stripped by the tune would turn to dust upon touching sunlight.
So, could the Bone Race be products of that piano solo?
Regardless, initially, there must have been the ability first, then the tune.
If there was such a thing as a complete form within the Bone Race, then the Bone Minotaur and Bone Nightmare before them were likely complete forms.
Tonpa had trained rigorously for two years, but against such complete forms of the Bone Race, he was utterly outmatched. At first encounter, he could only retreat to a corner and cheer for Law and Biscuit.
The Bone Nightmare's speed wasn't slow… in fact, it was very fast. When galloping, it emitted the crisp sound of bones clashing, somewhat ear-piercing.
Their attack method was very simple, only charging and slashing, back and forth. What they used to slash were the ribs the Bone Minotaur pulled from its own body.
Dodging such monotonous charges and slashes should have been easy.
After several exchanges, Law and Biscuit realized the Bone Nightmare and Bone Minotaur's attack patterns seemed fixed… simple and inflexible.
With this basic judgment, the two switched from defense to offense.
Dodging one charge, Biscuit struck first. She raised her sturdy arm, infused with full Aura, and punched the Bone Nightmare's side, forcefully knocking it back over ten meters.
However, the expected disintegration didn't happen. Only clear cracks were left on each of the Bone Nightmare's bones, which were as thick as thighs.
It was worth noting that Biscuit was in her transformed state now, having lifted her body's restrictions. Each punch was formidable, yet it only left cracks on the Bone Nightmare's bones.
This phenomenon made both Biscuit and Law frown. Even if it were Vein Stone, Biscuit's full-powered Aura-infused punch should have shattered it into pieces.
'Though the result wasn't ideal, a few more punches should suffice.'
Just as Biscuit thought this, under the light from the glowing algae, she saw the cracks on the Bone Nightmare's body rapidly healing.
"Self-healing ability."
Biscuit said grimly. Leaving aside the frightening hardness of the bones, this self-healing ability was truly cheating.
Law naturally saw this too. Though he hadn't truly attacked yet, he also felt it was a difficult situation.
"Biscuit, I'll take the lead."
Watching the Bone Nightmare turn around and charge again, Law raised his hand, and Shin suddenly appeared in his right hand.
Without waiting for Biscuit's response, the Domain spread from his feet, instantly enveloping the Bone Nightmare.
Law's eyes turned cold as he activated his Domain's ability. He didn't aim to crush the Bone Nightmare and minotaur into powder… just cutting them into pieces would suffice.
The Domain's ability poured onto the Bone Nightmare and Bone Minotaur. With light sounds, numerous fine cracks appeared on their bodies.
Even though his Domain's power and control had greatly increased after his breakthrough, it was still limited by the weakening due to range.
Once the En's range expanded, its power would weaken accordingly, which is an unavoidable flaw.
'Harder than Vein Stone?'
Law made a prompt decision to retract his Domain. At that moment, the Bone Nightmare charged again, but was easily dodged by Law, who simultaneously slashed at its side.
If Domain was a mid-to-long-range attack, then Shin was an absolute close-range weapon. The former's power was limited by range, while the latter was an absolute sharp weapon in close combat.
With one slash, the bone that Biscuit's full-force punch could only crack was severed and fell to the ground.
One bone fell, but the Bone Nightmare's mobility was unaffected.
It turned around again, and as if magnetized, it suck back the severed bone from a distance, reattaching it to its original position, healing in seconds.
Seeing this, the two felt quite puzzled.
That unreasonable ability had brought some trouble.
Looking at the intact Bone Nightmare and Bone Minotaur, Law's breathing suddenly evened out.
He took the initiative, adopting an offensive stance, gripping his sword with both hands at his side. His Aura stirred a faint breeze in silence.
"That is…?"
Biscuit watched Law's preparation, surprised.
Just then, Law moved. In the blink of an eye, he used Instant.
His figure, accompanied by blade light, flashed past and through the Bone Nightmare and Bone Minotaur.
Ssssh!
Nine slashes.
The Bone Nightmare and Bone Minotaur were cut into nine segments, falling to the ground.
Biscuit inhaled sharply. She barely saw the blade shadows, feeling that Law's progress was overly exaggerated.
As for Tonpa, he could only stare blankly. He saw nothing but knew Law had struck nine times in that instant… which was why he could only stare.
One pass, one powerful attack.
Yet, the severed bones automatically pulled back into place, restoring their original form.
Law turned around, looking at the intact Bone Nightmare and Bone Minotaur.
He was reminded of the Void he encountered on Demon Island, 'It felt like the same type. So, did it have to be settled with mental attack?'
However, considering the Bone Nightmare and Bone Minotaur's dead-set persistence from the start, if not dealt with, the journey would never be peaceful.
'Aura Intent might be effective, but before that...'
Law smiled slightly, stirring his full body's Aura. Instantly, behind him, a snow-white humanoid phantom appeared, holding a long blade.
It was clearly being used as a testing stone.