Shang was still visible, but the tortoise couldn't sense him.
That was because Shang had used the Light and Darkness Concepts to hide from Spirit Senses.
Yet, if one had eyes, they would still be able to see him.
But since the true tortoise was buried inside the thick layer of armor, it couldn't look at Shang with its actual eyes.
This essentially made Shang invisible to the tortoise.
At least until it somehow managed to look at the real world with its eyes.
And if it did that, Shang would very quickly realize where the real tortoise was.
The pressure on Shang's back reduced by a lot, but he still had to avoid the projectiles.
In a certain way, avoiding the projectiles now became even more draining on his concentration since he couldn't anticipate a projectile's trajectory anymore. After all, it was random.
But Shang still preferred it this way.
Shang recovered his Death Mana and used Injection to get as deeply into the tortoise as possible, but he could barely penetrate just a couple of kilometers of its ridiculously thick armor.
Once more, Shang couldn't win the battle because his Affinity couldn't be revealed.
If he could use his Domain of Entropy, he could dig through the tortoise's body while weakening the projectiles so much that his body could resist them.
Additionally, if Shang could use Fate, he could easily bisect the tortoise, which would allow him to pinpoint the location of the real beast.
But as things stood now, he didn't have enough power to break through the armor.
The stone and metal that the tortoise left in the arena quickly turned into Earth and Metal Mana again, which rapidly got reabsorbed by the tortoise.
Shang could try destroying the will on the Mana, but that wouldn't do a lot. The tortoise would just absorb more Mana from the ground and air.
After he considered all of this, Shang was actually glad that he had such an opponent.
This tortoise allowed Shang to work on his offense without being just a target dummy.
'The fish bird was a perfect opponent, and now this tortoise is also a perfect opponent. Is this just a coincidence?'
Shang wasn't sure.
It was possible that the Thunder King was sending in just the right opponents.
Shang continued fighting against the tortoise for several years, launching one attack after the other.
He was using the tortoise's armor as a way to gauge how strong his attacks were, and it proved to be quite helpful.
As the years passed, Shang managed to get deeper and deeper into the tortoise's body.
After 20 years, Shang managed to get two kilometers deeper than before. Assuming the real tortoise was in the middle of the bigger tortoise's body, Shang only needed to get through another six kilometers of armor.
Every time, Shang used a perfectly prepared Sword Heart with all his Death Mana using the Concept of Weakness.
Another 20 years later, Shang managed to get another two kilometers deeper.
In comparison to the beginning, Shang's attacks had become nearly twice as strong, which was a far bigger improvement than he had expected.
He wasn't using more Mana, and his body also hadn't grown in power.
And yet, somehow, his offensive power had increased by this much.
What had changed?
Shang analyzed the power of his attacks for a long time.
It was very difficult to say what had changed.
In comparison to learning Concepts, walking further down the Path of Sword consisted of less theoretical knowledge and more instinctual movements and feelings.
Shang just felt more comfortable with his attacks, and they also felt more "correct".
One time, Shang tested the power of his attacks without using any Death Mana, and what he saw shocked him.
Barely anything!
The power of his normal attacks had barely increased in the last 40 years!
At most, they were 10% stronger.
That obviously couldn't be compared to the 100% increase in power with Death Mana.
That was when Shang changed his thinking.
Shang was definitely making progress on the Path of Sword, but his progress wasn't as fast as he had thought. Or maybe, the progress just didn't have as much of an impact.
But when it came to attacks with Death Mana, his progress was astounding.
This meant one thing.
Shang wasn't only progressing on one Path.
He was progressing on two Paths, at least.
Shang decided to continue training like this, and ten years later, a subtle change occurred.
Shang's power stopped increasing.
His power had reached some kind of ceiling.
Yet, he continued training like this.
Ten years later, Shang's power barely increased by maybe 2%.
But Shang continued.
In the next 50 years, Shang's power increased by maybe 5%.
50 years later, maybe another 5%.
Shang had entered a rhythm, and he continued attacking absentmindedly.
Once more, Shang unleashed an attack without Death Mana.
Its power had increased by a bit, but not by that much.
However, after Shang felt his attack connect, he felt something.
There was something different about this attack compared to his normal attacks over a century ago.
When he had used Death Mana, Shang hadn't felt this difference since it was very subtle and since the Death Mana was overshadowing it.
Shang released another attack without Death Mana, and the subtle sensation appeared again.
There was something.
Something else.
Something Shang had never felt before.
It was a bit like Mana, but it wasn't Neutral Mana, and it wasn't any kind of other Mana.
No Neutral, Fire, Earth, Wind, Water, Ice, Lightning, Metal, Light, Darkness, Space, Time, Gravity, Life, or Death Mana.
Thanks to his Transformation, Shang could feel all kinds of Elemental Mana, and he was sure that this kind of Mana didn't belong to them.
But it felt like Mana.
It had the properties of Mana.
Where did it come from?
Shang followed the feeling and watched as the Mana appeared on his sword.
He wasn't sure where it came from.
BANG! BANG! BANG!
Shang rapidly attacked the tortoise in an avalanche of attack, trying to summon as much of this kind of Mana as possible.
This barrage of attacks continued for a couple of seconds.
And then, Shang realized something.
His mind was growing weaker!
This meant that this weird kind of Mana was using the Mana stored inside his mind!
So, Shang actively used the Mana in his mind and summoned the sensation of this new kind of Mana.
BOOOM!
It was like a floodgate had been opened, and a rapidly moving grey mist appeared around Shang's sword as he felt the Mana in his mind quickly diminish.
Now, Shang could feel the Mana very clearly.
It was Mana, but it wasn't any kind of Mana he had ever seen before.
It felt extremely sharp.
Just like a sword!
Sword Mana!
Shang lifted his sword and attacked the tortoise again.
BOOOOM!
All the Sword Mana on Shang's sword vanished, but the power of his attack had increased by over 50%!
Shang finally understood it.
His Mana entered his sword, which was then transformed into Sword Mana, and Sword Mana increased the power, reach, and sharpness of his sword without increasing its weight.
So, this was the level after Sword Heart.
Sword Mana!
But this was not where things ended.
As soon as Shang understood the existence of Sword Mana, something else also became clear.
Shang summoned his Death Mana and fused it with his Sword Mana.
Instantly, the Sword Mana turned black and stopped moving.
It was like a blade of obsidian had appeared around it.
Even more, the unstable Sword Mana and the unstable Death Mana seemed to connect with each other, creating something that was stable.
Shang attacked the tortoise once more, and what he saw shocked him.
His attack was as powerful as when he used Death Mana with the Concept of Weakness.
However…
The mix of Death Mana and Sword Mana on his sword was still there.
It hadn't been used up!
Shang refilled his storage of Death Mana. During that time, the mix of Sword Mana and Death Mana reduced by about 20%. It wasn't permanent, but it held for quite a while.
Shang put more Sword and Death Mana into his sword, but the mix of Sword and Death Mana only returned to its earlier amount. It wasn't possible to add more Sword and Death Mana.
But Shang quickly found the reason.
His sword could only create so much Sword Mana at once.
But the same wasn't true for Death Mana.
Shang added another layer of Death Mana with the Concept of Weakness on top of his sword.
Now, his obsidian-like blade also had a black glimmer on its edge.
Shang attacked the tortoise.
SHING!
And bisected it!
