External Soul Bones were actually the easiest to identify.
First, Bone Douluo could confirm that the segmented bones surrounding Gu Yang were not human bones, so the possibility that came to mind was a Soul Bone.
Conventional Soul Bones covered six major parts: the most precious Torso Bone, the Head Soul Bone, and the four limbs.
This strange Soul Bone clearly did not belong to any of those six parts, so the answer was naturally obvious.
Thus, it was no surprise that Bone Douluo recognized it as an External Soul Bone at once.
Segment after segment of bone encircled Gu Yang. Only after a moment did the end of this unusual Soul Bone become clear: like the Dark Devil Tiger's tail, it actually bore a scorpion's hooked stinger.
The Dark Devil Tiger's External Soul Bone, the Dark Devil Tail!
The Dark Devil Tail swayed slowly. Under the effects of Shikotsumyaku, it was even more docile than a Soul Ring, without the slightest discomfort or resistance.
Although he had only just absorbed it, he could already wield it almost as naturally as his own arm.
Obtaining the External Soul Bone, the Dark Devil Tail, was an unexpected windfall for Gu Yang.
As Gu Yang familiarized himself with his newly acquired Fourth Soul Ring and External Soul Bone, the Dark Devil Tail, he was just about to put the latter away.
A sudden change occurred.
The previously docile, obedient Dark Devil Tail abruptly began circling Gu Yang at high speed.
The Dark Devil Tail going out of control was one thing, but the next moment, Gu Yang discovered that his first Soul Skill, Bone Armor, had also activated on its own, beyond his control.
After his first Soul Skill, Bone Armor, even his Head Soul Bone slowly emerged as well.
Fine strands of connecting tissue actually extended between the Dark Devil Tail and the sixty-thousand-year spiritual skull, fastening directly onto the semi-humanoid skeleton of his first Soul Skill, Bone Armor. Instead, they gave it a hint of the vitality of flesh and blood.
"This is..."
Bone Douluo was dumbfounded. What was happening to Gu Yang at this moment was already well beyond his knowledge.
Although the transformation produced by combining the two Soul Bones felt like an unfinished product that left something to be desired, Gu Yang could clearly sense that his first Soul Skill, Bone Armor, now had considerably greater defensive power.
He could use all his skills with greater ease, and every skill received a certain degree of amplification. Most importantly, the Soul Power consumed when he used his Soul Skills had fallen drastically.
Considering the various changes in himself, Gu Yang instead arrived at a guess.
Could this be a Soul Bone Fusion Skill?
According to Gu Yang's understanding, a Soul Bone Fusion Skill was an additional skill produced when one's Soul Bones fused together, and its effects even surpassed those of a Martial Soul Fusion Skill.
Thus, the conditions for its appearance were extremely demanding. First, one had to gather all six Soul Bones, and only then was there a minuscule chance of a Soul Bone Fusion Skill appearing.
Of course, the greater the compatibility between the Soul Bones, the greater the chance of a Soul Bone Fusion Skill appearing.
It would be ideal if the Soul Bones came from the same Soul Beast.
Yet his spiritual-type Head Soul Bone and the Dark Devil Tail clearly had no connection whatsoever. Logically, the chance of a Soul Bone Fusion Skill appearing should have been infinitesimal.
Even Tang San in the original story had only stumbled upon a Soul Bone Fusion Skill after gathering four Soul Bones, including two Hundred Thousand Year Soul Bones.
Whether in quantity or quality, his Soul Bones clearly fell short of Tang San's at that time.
Could it be that I'm simply luckier than Tang San?
Rather than believe in so-called luck, Gu Yang preferred to attribute all of this to his Shikotsumyaku.
After all, under the effects of Shikotsumyaku, anything involving bones or related to bones had changed.
Even a Ten Thousand Year Soul Bone could have two skills, so Gu Yang could readily accept activating a Soul Bone Fusion Skill with just two Soul Bones.
The External Soul Bone, the Dark Devil Tail, was likewise forty thousand years old, and it had still given Gu Yang two Soul Bone Skills.
Shadow Assault and Darkness Domain.
Shadow Assault allowed him to completely conceal his presence within the perception range of a Titled Douluo-level Soul Master and launch a sudden attack without anyone noticing.
While concealed, Shadow Assault's attack power exceeded his own attack strength.
Darkness Domain condensed an area of inherently corrosive darkness elements, continuously weakening and corroding the enemy's Soul Power within its range.
"Brat, are you all right?"
Only when Gu Yang's condition began to stabilize did Bone Douluo speak, interrupting his thoughts.
Gu Yang shook his head slightly. "Grandpa, I'm fine."
"As long as you're fine. The way you looked just now really had me worried," Bone Douluo said, still shaken.
Since Gu Yang's Martial Soul Awakening and his acquisition of Soul Rings, this had definitely been the most perilous occasion.
"Right, after taking such a huge risk this time, your fourth Soul Skill shouldn't be weak, should it?"
After learning about his fourth Soul Skill, Gu Yang explained its effects to Bone Douluo as well.
"Grandpa, my fourth Soul Skill is Fear Roar. It uses sound waves to make the targets' spiritual power tremble, inflicting a group stun. While stunned, enemies can't take any action."
"The weaker the enemy's spiritual power, the longer the stun lasts. Conversely, the stronger their spiritual power, the shorter it lasts. But no matter how powerful the enemy is, Fear Roar can still inflict a stun lasting nearly two seconds at minimum."
Two seconds of hard control?!
Gu Yang had explained it in great detail, so Bone Douluo immediately noticed what made this Soul Skill so powerful.
Having the duration of a stun depend on the strength of an enemy's spiritual power was actually quite common among control-type skills.
What was truly terrifying was that it could impose two seconds of hard control no matter how powerful the enemy was.
For a control-type Soul Master, this was simply a godly skill.
It meant that even a Titled Douluo facing this Soul Skill of Gu Yang's would have to endure two seconds of stunning control.
Taking it a step further, if he faced a god, then by its literal description, could it forcibly stun and control them for two seconds too?
Two seconds were more than enough to determine the outcome of a battle.
Bone Douluo could recognize how powerful this Soul Skill was, and Gu Yang could think of it too. In fact, Gu Yang's thoughts went even deeper than Bone Douluo's.
If, according to the AI's analysis, gathering the powers of seven attributes really can transform my Shikotsumyaku into All-Killing Ash Bones...
Then when facing an enemy, couldn't I forcibly control them with Fear Roar, then rely on the formidable destructive properties of All-Killing Ash Bones to kill them instantly with a single stab?
Uncounterable? Invincible?
Gu Yang truly felt that way.
Douluo Continent was, after all, the bottom of the barrel of fantasy worlds. This world's setting was actually pathetically weak, and All-Killing Ash Bones should be able to break down and destroy everything.
The key was whether he could successfully awaken All-Killing Ash Bones.
Of Douluo Continent's seven attributes, Gu Yang had already gathered earth, fire, light, and darkness. Only wind, water, and space remained.
He was already more than halfway there. Whether it would work would be settled when the time came.
"All right, brat, stop thinking about it for now. You can take your time familiarizing yourself with your Soul Skills and Soul Bone Skills once we get back." Bone Douluo looked at Gu Yang with a smile, his mood greatly lifted as well.
One Soul Skill, one Soul Bone Fusion Skill, and two Soul Bone Skills. Gu Yang had really struck it rich this time!