The next day, word came from the laboratory.
They had managed to find out the identity of the drug in the demon beast’s body.
Basically, the drug was made using material which could be collected from the Previous Demon Lord’s Territory. It had the effect of forcefully mutating an organism.
The result was as I expected.
So the humans in the Republic went to the Previous Demon Lord’s Territory to secure the ingredients for the drug.
They were looking for water and plants with a high concentration of miasma.
If they research it for years, the laboratory might be able to produce a drug with similar effects.
Of course, it was a big problem from a moral perspective.
While there were many kinds of illegal potions, none of them were capable of this.
It was the migration of drugged people to foreign cities that sparked the demon beast outbreaks.
There seemed to be a time lag before the drug triggered, so nobody sensed anything amiss until the transformation began.
The manufacturer of the drug was quite thorough on making it hard to detect.
They must have possessed an aptitude for magic.
To think they managed to spread all those people and trigger the demon beast outbreak without anyone noticing until after the fact…
While it sounded weird for me to say, considering I also turned people into the undead and dominated them, this kind of act was inhumane.
I mustn’t allow the world to become a place where people could easily do such a thing.
I need to put an end to it quickly.
The laboratory referred to said drug as the "demon beast drug," and they would continue to analyze it in the future.
Currently, they tried to develop a drug to counteract its effects.
While it was doubtful they would succeed, we should try to do so anyway.
There was also a miniscule chance such a drug might be administered to my subordinate.
It would be a problem if that happened and I was unprepared.
Since we know the cause, we better create countermeasures from now on.
The counteracting drug is important, but I also must prepare the fundamental solution.
If I kept waiting to act, the damage would only increase.
I needed to catch the mastermind as soon as possible, but I still didn’t know where they were located.
Even so, there were some actions I could take.
The easiest of all was to go and destroy the Previous Demon Lord’s Territory where the drug's ingredients came from.
Such raw material couldn’t be cultivated easily.
Those ingredients only managed to grow there because of the miasma and the magic power of the area.
Recreating such an environment anywhere else would be a daunting task and unrealistic to achieve.
That was the reason why the humans from the Republic had to go all the way to the Previous Demon Lord’s territory.
They went there to secure the ingredients to make the drug.
Once they couldn’t collect the raw material anymore, they could only produce the demon beast drug with the material already in their stock.
That would reduce the production speed significantly, and they would have no choice but to compromise their own plan.
In the meantime, I would find the mastermind.
Once I discovered who was responsible for all of this, I could just eliminate them.
There were only a few who could match me in combat.
Unless they had an irregular existence like that of the Great Spirit, I doubt it would be a hard fight.
I could finish it quickly as long as I found the culprit.
After that, all I needed to do to end this turmoil was collect all the demon beast drugs they had and capture the people who were affected by it.
At that time, the door of the audience room opened.
The one who appeared from the other side was Grom.
He didn’t seem to be panicking, but also didn’t seem to have anything to report to me.
I asked Grom.
“What is it?”
“I was just wondering if there was something I could help you with, so I came to ask Demon Lord-sama about that.”
Grom said as he looked at me.
Since the Demon Lord’s Army couldn’t be moved at present, he tried to contribute in his own way.
He felt he couldn’t stay idle, so he went directly to me to ask for instruction.
“I see. Thank you for your concern.”
I gave him my honest thanks.
Grom was being the loyal vassal as he usually was.
I didn’t want to waste his eagerness here.
I was about to go to the Previous Demon Lord’s territory, but since Grom was already here, I might as well make him help with that.
I asked him.
“It isn’t a job in a strict sense, but there’s something I want your help with. Can I ask for that?”
“Of course you can. This Grom would gladly jump into flame if it was for Demon Lord-sama‘s sake!”
Grom triumphantly answered.
Even if he jumped into the flame, he wouldn’t be affected much by it.
He would just walk calmly through the fire.
However, his words just now were to show his loyalty.
It would be boorish of me to point that out.
Grom and I traveled to our destination from the castle.
What lay beyond was the dark wasteland of the Previous Demon Lord’s Territory.
Grom looked around.
“This place is…”
“It’s the Previous Demon Lord’s territory. For now, we need to do something about this land.”
“What are we doing here exactly?”
I responded to the Grom’s question using the answer I had already prepared.
“We will purify the atmosphere here and thoroughly destroy the territory. I will make sure this land can never produce that raw material ever again.”
I was thinking about it back in the castle. It was something I should have prioritized over the countermeasure against the demon beast drug.
If I turned this place into a dead land where even grass couldn’t grow, it would be difficult for them to produce more of the drug.
At the very least, it would make mass production impossible in the near future.
Grom uttered in an admiring voice while stroking his chin.
“Hohou… That is a bold move yet again. As expected of Demon Lord-sama.”
Grom praised me, but his movement was unnatural.
He behaved as if searching for something.
Perhaps he was trying to adapt to the atmosphere of the Previous Demon Lord’s territory.
This land was quite special.
So special that it was harmful for humans.
While this location was a comfortable environment for a top-ranked immortal like Grom, he still needed some time to adapt.
Once Grom calmed down, I gave him my instructions.
“For now, let’s try to absorb the miasma around here.”
“Yes, I understand!”
Grom nodded and stretched his eight arms.
He stood still and began to concentrate.
The magic power and miasma in the air absorbed into his body.
Soon Grom fell to one knee and moaned painfully.
“Guh… This, is… quite tough, isn’t, it…”
A body would reject miasma that wasn't its own.
The feeling of foreign objects messing about inside was very painful.
It felt like it tore you apart.
Perhaps even one’s soul might be eroded.
I also experienced the same thing at the Valley of the Dead.
That was the reason I could understand Grom’s agony.
“The burden will be lighter once you get used to it. Bear with it somehow.”
“De, Demon Lord-sama…! GUOOOOO! THIS IS NOTHIIIIINNNNGGGG!”
Grom screamed as he stood up.
Immediately after, his absorption became stable.
The surrounding miasma grew thinner until it eventually disappeared from the vicinity.
All of it was absorbed by Grom.
“Fumu, it looks like you’re successful.”
“Haa, Haa, Haa…”
Grom breathed heavily.
He was considerably exhausted after doing so.
He shouldn’t be able to breathe since his body consisted of only bones, but he was still running out of breath.
It was unknown how that was possible.
“Are you okay?”
“O, of course I am… I, I could still go, on…”
“You better rest for a bit. I’d also like to ask you to absorb the miasma in other locations. I will go elsewhere to purify the atmosphere."
“Roger, that…”
Grom sat on the ground.
It would take some rest before he was rejuvenated.
I left him and moved away.
After that, the miasma and magic power contained in the atmosphere of the Previous Demon Lord’s Territory was completely eradicated.
I also killed the few remaining demonkin there. Then I used a series of forbidden spells to destroy the territory.
Grom also joined in during the middle of it, which dramatically increased the speed of the destruction.
Thus, we turned the Previous Demon Lord’s territory into a true wasteland.