Fortunately, Isabella was not as crazy as to collapse a large part of the tunnel. Instead, she just collapsed a small part, separating the creatures from them.
Bloed then understood what Isabella meant by 'just in case' when she chose this part of the tunnel to combat the creatures.
Isabella had likely noticed that the magic circle in the wall she touched could collapse the tunnel, so she planned to use it if the enemies were too strong for them.
Even so–
"We need to leave this place," Isabella said with a grave expression. "We don't know if the creatures can dig through the debris or if they know another way towards here, so we need to leave before they catch up to us."
Bloed, Aya, and the others nodded.
Immediately, the group started to run as they searched for an exit.
"Dammit, what in the hell are these things?" One of the members of Isabella's club asked.
"I don't know," Isabella said. "But whatever they are, they are very dangerous."
Bloed and Aya looked at each other and remained silent.
They could not reveal the identity of the creatures to others easily. After all, everything related to the Blight was highly sensitive, and it would be bad if many people learned about it and panic spread.
At that moment, Isabella looked at Bloed.
"Bloed, the technique that you used to cut the creature. Can you teach it to me?"
Bloed smiled wryly and shook his head. "I can't. It's not a technique that you can use. In fact, nobody but I should be able to use this technique in this world."
"Is it so?" Isabella nodded and did not ask anymore. "Such a shame. Perhaps I could use it to find a way to injure that creature."
Bloed smiled bitterly.
That was the most terrifying part about devourers. Practically every kind of attack except physical ones were completely useless against them.
Moreover, just like the creatures just now, their abilities were not limited to absorbing energy. They usually had strong bodies and the ability to use the energy they absorbed, making them extremely dangerous.
The best example was the smaller creature that they fought just now. In all honesty, it was not very strong. It was just at the late stage of A-Rank.
If Bloed and Aya went all out, they should be able to kill it after a bit of trouble. As for Isabella, normally she could kill tens of creatures as strong as it easily.
However, the situation was completely the opposite when it came to that creature. Bloed and Aya would have been killed if they fought it by themselves (Unless Bloed used [Overdrive] or his last use of [Imaginary Slash]). Isabella, on the other hand, could not use most of her spells against it, so she could not defeat it either.
The only two spells that she could use against the creature were two spells that she created just a few hours ago when she realized that they could absorb mana. Even so, they were much weaker than Isabella's normal spells. In fact, she could not show even a tenth of her true strength.
Of course, that in itself was impressive. Any other mage of her level would have been completely helpless against that creature.
That showed why this world fared so poorly when the Devourers appeared one hundred years ago.
"... If only we have a method to restrain it, Bloed could kill it," Aya murmured.
Isabella and Bloed smiled wryly. That was easier said than done.
"… I can try something." Isabella said after thinking for a moment. "However, I don't know how effective it will be. All the restraining-type spells that I know use mana directly. It's useless against these creatures."
"It's the same with me. The only thing that I can use to hurt them is my saber, the rest is useless. Aya is even worse, she can only throw things to be of a bit of help."
Bloed, Aya, and Isabella smiled bitterly.
As for the other two members of Isabella's club, they could not even smile.
After all, they had been completely useless in the previous battle.
Just at that moment, the group arrived at a part of the tunnel where it branched into two paths.
"Two paths, huh." Isabella furrowed her brows.
Bloed thought for a moment and closed his eyes, focusing on the tunnels in front of him. One second later, he opened his eyes and looked at one of the tunnels.
"I think we should choose this one,"
"Huh? Why?"
"The flow of wind is stronger in this direction. Perhaps it leads to an exit."
Isabella was startled. She looked at Bloed in surprise and chuckled.
"You are pretty knowledgeable, huh. Very well, we are taking this path."
Unfortunately, even after five minutes of walking, they did not find an exit. Instead, they found several other points where the tunnel branched out.
Just like before, they chose the tunnel where the flow of wind was stronger, but even so, they failed to find an exit.
But when the group was starting to lose hope, Bloed, Aya, and Isabella stopped abruptly.
Then, they looked in front of them.
"Light," Bloed said.
Aya and Isabella nodded, and the eyes of Isabella's club members brightened.
But after the group advance for a few meters, Bloed frowned.
It was because the flow of wind was not as strong as it should be if they were near the exit.
Isabella seemed to have noticed it as well because she furrowed her brows and started to circulate her mana.
"Be careful. Something is wrong."
"I'll take the lead," Bloed said.
He then walked forward slowly, making sure to walk as slowly as possible.
And then, he saw the end of the tunnel.
But when Bloed looked beyond it, his eyes opened wide.
Because after exiting the tunnel, he saw an enormous underground structure supported by several enormous pillars.
The structure was immense. So big that Bloed wondered how it was built underground.
But what surprised him the most was the glass tubes filled with a strange liquid that he saw inside the structure.
"This is... A laboratory?"