Stop, Friendly Fire! Chapter 8 part3

Did the Great Slime (+3) already wipe out all of the slimes as it passed by? It was so silent that it felt as though his noisy fight at the beginning with the Great Slimes was a lie.
'Moreover, this place conversely doesn't have any filth. Ah, was it all melted by the acid?'
When a slime becomes a Great Slime, the acid that its spews out becomes stronger. It would melt solids, and evaporate liquids; the slimes that spew out this horrific acid were crawling around, so it was only natural that the sewers become clean. But around this time, he wondered why the sewer passageway was still left intact.
'I know it's tough, but the fact that the preparations were this thorough... perhaps the Empire treated it as though it was natural for slimes to appear in the sewers.'
When the Empire flourished, he wondered what it looked like, and suddenly couldn't get it out of his mind. He would probably never know and... he smiled bitterly (that's roughly what he imagined his expression was) and continued to explore.
"...Hmm?"
However, while he was exploring, he discovered a crack carved into a portion of the left passageway. When he thoroughly inspected it, he found that the crack was in the shape of a square, and it was a size that could comfortably fit the palm of his hand.
And at the center, he saw the traces of hidden mana. They seemed to be an extremely old.
'Is this perhaps...'
It looked like a fingerprint scanner that showed up in movies... Lee Shin Woo pondered briefly, but soon placed his hand atop the square. Then, the square pattern surprisingly emitted heat and slightly came out. Beyond any doubt, it was a lock!
"Hoo...!"
Lee Shin Woo was excited, thinking that he'd found a secret hidden within the dungeon, and immediately emitted mana, but the reaction wasn't great. The door lock turned red, and emitted an ominous light, though that was all. Nothing else really changed.
Of course, he had roughly expected that. It was a lock, so there was no way it'd open by just emitting a bit of mana.
However, be that as it may, he thought that this structure didn't just respond to a certain individual's mana alone. That's because he could faintly, very faintly, feel the traces of mana from a variety of humans that had stood before this very lock.
'Then... is it a pattern as expected?'
Unlocking it had now become difficult. It'd probably been dozens of years since the last time this lock was activated, and was so terribly worn out to the point that it'd be difficult to ascertain the origin of the traces of the time worn mana.
The saving grace was that there were countless traces of people's mana, and their strands of mana all overlapped; if he were able to analyze the flow of mana, he felt as though he'd obtain a meaningful result.
'It'll probably be a lot of work, but... shall we?'
There should still be some time left before the Great Slime cleans up this dungeon. Lee Shin Woo concentrated on the door lock and began to thoroughly analyze the traces of the faintly remaining mana.
'Figuring out a starting point is important. Yeah, here... No, is it here?'
He saw the conditions of opening the lock as follows: draw the mana to the center of the palm, and use that mana to create one pattern. Of course, it wasn't just that it had to be the same pattern, but it had to flow from the same starting place and end at the same ending place.
He genuinely activated his senses and by analyzing the door lock's release conditions, he found and excluded the false traces that they had purposefully put in. He had fun, as it felt as though he was playing some sort of puzzle game.
[The Low Rank Magic Accumulation skill has become Lv2. Magic has increased by 2.]
"Ah, it goes up."
It was the same process as when entering a dungeon, so perhaps by just carrying out these tasks, his proficiency in magic related skills would increase.
Lee Shin Woo, who was motivated to improve his skills and stats, didn't even know how amazing what he was doing was, and continuously analyzed the lock. And then, he finally succeeded in determining the pattern.
[The Low Rank Magic Affinity skill has become Lv8. Magic has increased by 5.]
"It's a skull. What completely bad taste."
He knew approximately what the people who had gathered here came for. However, to think that the pattern that they used was a skull; the laughter came out naturally. It definitely should've been fairly difficult to get through, though...
'In any case, I just need to find the starting point and the end point now.'
They had gone so far as to hide it in the sewers and even maintain thorough security over it, so he probably wouldn't get through scot free if he got this wrong. Lee Shin Woo took a deep breath and concentrated even harder on the pattern. To be exact, he concentrated on the flow from the traces of mana that the humans had left behind dozens of years prior. However, there was no way it'd be that simple.
'Damn it...'
He gritted his teeth. Lee Shin Woo thought he might've been too arrogant to attempt this, as someone who hasn't handled mana for very long.
However, despite that, he couldn't give up at all. In the end, it was pretty much a miracle finding the right pattern. He had no choice but to trust in his talent and concentrate right now...!
'Ah!'
Lee Shin Woo concentrated more forcefully on the pattern, even more than when he had taken the national college entrance exam, and at that moment, he miraculously succeeded in grabbing a hold of a faintly remaining flow of mana. It was truly a small trace, but it seemed as though some traces of mana were being absorbed into the pattern.
Lee Shin Woo could even go as far as to guess the owner of that mana, and he had very briefly assimilated their experiences... it was none other than the magician, Gerrit, who had burnt and killed his zombified teacher.
'Wait, it's the opposite. Since it was a trace from Gerrit, I was able to recognize it. I also experienced sharing a body with him as well, and... more importantly, the fact that Gerrit came here means that this facility is related to General Seagald.'
He knew that Gerrit wanted to meet with General Seagald from the memories of the bone he had acquired.
It was a facility within the interior of the sewers where they performed some kind of research, and Seagald and Gerrit... He couldn't be sure of anything yet, but Lee Shin Woo drew a truly persuasive scenario in his head.
"Then let's uncover what the secret is."
Since he had uncovered a trace of the flow of mana, it was easy to find the rest of the traces. In his head, a series of streams of mana were cleanly connected!
'I got it!'
He inwardly yelled with delight and placed his hand carefully on the door lock; and after going through the simulations in his head several times and making sure... reproduced that flow. The slightly black dyed mana slowly and carefully started to create the pattern of a skull.
Eventually, the pattern was completed, and thankfully the door lock didn't become hot. It emitted a delicate blue light, and soon was sucked back into the wall; at that moment, a larger square pattern appeared. It was a door that allowed him to enter the secret room!
[Releasing door lock.]
It was a miracle; he had revived something from several years ago... A part of lost history had been revived due to Lee Shin Woo, and it was at that moment that the mana within his body intensified, surged, and exploded.
The countless, dormant knowledge fragments and his talent connected, causing a big bang that he couldn't contain!
[You have acquired the passive skill, Magic Tracking Lv1! Magic has increased by 3.]
[Low Rank Magic Affinity, Low Rank Magic Accumulation, and Low Rank Magic Tracking skills have compounded and evolved.]
His ability to sense magic, accept it, and track it were all connected into one. A method of more effectively producing mana, circulating it, and utilizing it instinctually rose up into his head.
It was something that he couldn't have even dreamed of until now, as well as being absurdly complex and headache inducing, but... it was possible for him now. Lee Shin Woo nodded his head and accepted the mysterious feeling. He accumulated the knowledge and applied it.
[You have acquired the special passive skill, Low Rank Mana Bone Lv5! Magic has increased by 30.]
At that moment, mana indiscriminately spread through his body, covered his bones, and caused a fundamental change!
[Low Rank Mana Bone Lv5 (Passive)]
[Originally, humans were organisms that did not welcome mana, and through their strong tenacity as well as their talent, they realized a method to harmonize with mana. In order to more perfectly handle the mana that spread throughout the body as it pleased, the mana is accepted, created, and circulated by an imaginary organ that covers the heart. They called it the mana heart.]
[However, you are a skeleton without a heart, so you have done something outrageous and substituted the mana heart with your entire boney body. That scale is truly enormous, and if you did not have a considerable understanding and handling of mana, it would've been impossible to even attempt.]
[By achieving a balance between the vast knowledge, your talent in mana, and the special situation, this astonishing skill was born, and no one besides yourself knows the growth potential of this astonishing skill.]
It was truly an odd feeling. It felt as though he had taken off some unnatural clothes and he'd been thrown into a world filled with mana, naked. His body, composed of 206 bones, was integrated with mana and each of those individual bones were now more closely connected.
Of course, controlling all 206 bones simultaneously while controlling the mana was certainly not easy. Even if he was aided by the skill, there was way too much to focus on at one time, and he was afflicted with pain that felt as though he was being split apart.
It wasn't a joke; if he were to lose control and was flooded by the mana, it wouldn't be strange for his bones to shatter. He would have to constantly exert himself to adapt to this skill from now on.
[The invigorated flow of mana increases the body's reaction speed.]
[The invigorated flow of mana shortens the activation time of all skills.]
[You have successfully absorbed some outside mana and stored it. Mana has increased by 1.]
However, enduring the pain was bound to lead to sweet rewards. He'd only tasted a portion of it, yet it wasn't hard to realize that the effectiveness of his mana increased by more than several times. Even manifesting, collecting, and producing mana had increased!
For the first time, Lee Shin Woo felt like he had the right to call himself a hero. And... that qualification wasn't just this.
[At only level 3, you have acquired a portion of the qualification necessary to walk the path of an Archmage, one who naturally commands nature and changes the world. Magic has increased by 20. You have acquired the Archmage's karma token.]
[Quest complete! You have acquired 1 Lv6 Weapon Trickster's arm bone.]
[You have already achieved the Trickster's karma, but you are merely at the level of a toddler. The more personas you acquire, the more your strength grows. That is the path you have chosen, as well as the karma you have been bestowed.]
"Hoo..."
He had just been trying to find the secret room, yet had experienced a sudden change, one that he couldn't dream of; even after calming down the rushing mana, he momentarily stood still in order to get a hold of himself.
Lee Shin Woo kept control of the mana and circulated it. He felt the mana that his bones harmoniously spewed out as well as the resonating external mana so clearly that he thought that he would feel nauseous with the slightest slip. He likened this feeling to that of riding a roller coaster.
'I'd rather just vomit, but these damn bones won't let me.'
It wasn't an issue that could be dealt with in a short amount of time, though thankfully it was a problem that could still be solved. Just like how a human isn't usually aware of their breathing or the blinking of their eyes, but still does so naturally, he was training the control of his Mana Bone skill in order for it to operate unconsciously.
'Talk is cheap...'
Lee Shin Woo smiled bitterly and stayed in place for the moment. How much time had passed? At around the time where his head still hurt but he could move it like usual, Lee Shin Woo sighed in relief and checked the bone he had gotten as a reward for the quest.
[Lv6 Weapon Trickster's Arm Bone]
[A Trickster's arm bone, that was used as a weapon to cajole their enemies. There is enough recorded within to reform one's existence.]
"Huh..."
It was overwhelmingly distinctive compared to the other bones he had absorbed thus far; he couldn't suppress his admiration of the bone as he inspected it. It had an awfully large amount of mana within, was obviously extremely tough, and the fact that each of its finger bones was a different shape was especially distinctive.
Perhaps the Trickster was an existence that didn't need a weapon. He decided that it would be important to figure out how this weapon was connected to the Trickster; for now he'll reinforce...
[The activation of the skill has failed. You are not prepared to accept the strength within the bone yet.]
'...Ah, this pattern finally came up.'
He was already a bit prepared for this, but since it actually happened, it tasted bitter. If that was going to happen, he wanted to complain and ask why they gave him such a mouth watering bone at this time, but when he thought about it in another way, he felt like he was that amazing to have cleared a quest that was so far above his level.
'Well, it should be possible soon.'
If Bone Reinforcement couldn't accept it, then he would have to forget about this bone for now. Lee Shin Woo inspected the bone with a deeply regretful expression, and in the end, put it into his inventory.
Well, he already had his hands full adapting to, and applying the Mana Bone skill he had just awakened. It might've actually turned out well for him. Lee Shin Woo convinced himself of this and raised his head.
The secret door that had revealed itself for the first time in dozens of years looked worn out.
'Alright.'
Lee Shin Woo firmly resolved himself and placed his hand atop the door. The door silently rose up, to the point that it was difficult to believe that it had lain undisturbed for dozens of years.
The records of General Seagald, and the records of the research related to Gerrit...! Thinking that the secret was right before his eyes caused him to feel excited once again, but before Lee Shin Woo's eyes was...
[Keuhaaaaaaahk!]
A skeleton without an inch of flesh remaining popping out and attacking him!