After hearing Isao's words, Subaru, Kasumi, and the Realizers of their organization were furious. Even though he said that the League of Heroes didn't use humans as experiments, they still did after the serum finished. They couldn't accept that because they thought what the League of Heroes had done was inhumane. The Realizers wanted to say something to him, but Isao opened his mouth first.
"Please listen to my words before you get mad at me! They used the serum on their own accord; we have their approval. So the League of Heroes never forces them, let alone threatens them. Those people want to be the object of experimentation to multiply their power. They had been stuck as a low-level Realizer for a long time and wanted to increase their phase to become a high-level Realizer." Isao quickly explained before the Realizers from the Holy Union and Belial Alliance got mad at him.
"What happened after they used the serum?" Subaru asked seriously. If something bad happened to the Realizers after using the serum, he would report the matter to the Holy Union and have the organization act strictly on what the League of Heroes had done.
"Unfortunately, we failed. We couldn't power up a Realizer by using that serum. But you don't need to worry. The people using it are fine; nothing strange has happened to their bodies." Isao replied and sighed heavily.
"If that's the case, why are you using it on monsters instead? Are the words of the masked person true? Does your organization intend to increase its power by using monsters?" Subaru wanted to know why the League of Heroes had changed their experiment target. Kasumi just kept quiet because his question represented what she was thinking.
"We are..." Isao wanted to answer, but Theta interrupted him.
"Didn't I already tell you? The League of Heroes wants to increase its strength by using these monsters and outperforming the other two organizations. Why don't you guys believe me?" Theta suddenly jumped into their conversation and tried to convince Subaru and Kasumi.
"If you talk any more nonsense, I'll rip that rotten mouth of yours!" Isao roared angrily.
"Hahaha!" Theta laughed in response to Isao's words. He no longer spoke to sow enmity between them because doing so would make them suspicious.
"We didn't do that on purpose. We thought that if the serum couldn't be used on Realizers, all our research would be in vain. So we decided to try it on another subject: monsters. If the serum does not affect humans, what happens when we return the modified DNA to the monster in question?
The result was just as that bastard had said. The monsters we injected with the serum mutated instead of evolved. They gain intelligence, and their strength also increases. Unfortunately, the success rate is very low. Most of the monsters died, and some went into a berserk state, so we had to kill them. That's the reason the serum was created." Isao looked at Subaru and said.
"I see. Even though the serum was created accidentally, League of Heroes will receive criticism from various parties if the information is leaked to the public. The Japanese government and the five strongest Realizer groups might step in to deal with the problem. If that happens, the League of Heroes will get a severe punishment. No wonder your organization is eager to catch the masked person and kept it a secret from us." Kasumi finally understood why the League of Heroes wanted the mission to be a secret and only certain Realizers could participate.
"Ah, the Kinzoku family won't put pressure on the League of Heroes since we did the research together with them." Isao responded to Kasumi's words and smiled bitterly. After that, he glanced at Chizen. He had been quiet ever since Theta and the Wyvern appeared because he couldn't open his mouth when the leaders of the organizations were talking.
"What!?" Subaru and Kasumi were surprised after hearing that. They turned their eyes towards Chizen. Now they understood why the Kinzoku family let their talented young genius participate in the secret mission.
"Had the Wyvern been injected with the serum the masked man stole from the League of Heroes?" Kasumi quickly regained her senses and asked Isao.
"Yes, you're right." Isao nodded, and his face was furious. He was angry because Theta had used the serum he stole on high-level monsters. If those Wyverns go berserk and wreak havoc in Kyoto, then the League of Heroes will not be spared because the serum is their creation.
"No wonder I feel that Wyvern has become stronger than usual. So the serum can be used on any monsters?" Subaru asked with a solemn face. If what he thought was true, then the serum would be extremely dangerous in the hands of the terrorists from the Ghost Nebula. Those people would inject it into various monsters and use them to wreak havoc on Japan.
"No. the serum's success rate was minuscule even for low-level monsters. You can see that the mutation of the Wyvern is imperfect. If the transformation of the serum were successful, then the Wyvern would gain intelligence, and the bastard would have difficulty controlling it. Besides, the monster's physical condition shouldn't be like that.
The Wyvern looked more like it had entered a berserk state than mutated. But I wonder how they can control monsters in such a state." Isao shook his head and explained. He was one of the research site's chief guards and knew much about the serum.
"How did that masked person steal that thing from your research site? shouldn't the headquarters of your organization be heavily guarded?" Subaru posed another question to Isao. He was still confused about how Theta could steal something from the research area of the League of Heroes headquarters, which had a very high-security level.
"That person is posing as one of the scientists. On top of that, he has many spies within the headquarters of our organization. So he can act freely and get the serums easily." Isao gritted his teeth and answered in frustration. After all, he was one of the chiefs of the guards. So Isao felt useless when someone could infiltrate a research site and steal something from the League of Heroes.
Subaru and Kasumi looked at each other and nodded. They already knew what they had to do after listening to Isao's explanation.
"Then, we have to catch him no matter what. We can't let that guy use those serums on monsters. If that happened, the situation would become very dangerous, and the terrorists would become increasingly rampant in Japan. I couldn't imagine the damage and the number of casualties that would fall if the monsters they had suddenly mutated.
Luckily, we kept chasing after him and didn't let him use the serum on multiple monsters." Kasumi said to Isao. Although she didn't like how the League of Heroes had hidden the matter from them, the most important thing now was to catch Theta because the serum was so dangerous in the hands of terrorists.
"Yes. After we catch that person, I want you and the League of Heroes to give our organization a more detailed explanation." Subaru said seriously. He was willing to work with the Realizers of the League of Heroes, but he still felt disappointed in them.
"I understand. I will inform the higher-ups of my organization about this matter. In that case, we'd better catch him now." Isao nodded and quickly agreed to their words.
"Are you guys done chatting? If you still have something you want to talk about, then I can wait for you." Theta smiled and said playfully. He didn't care what they were planning because he was confident they would never catch him.
"Are you sure you can still talk like that in this situation? Are you trying to catch us off guard and looking for a chance to escape? Do not dream!
We have surrounded the Amanohashidate area by deploying hundreds of Realizers specializing in close and ranged attacks. You won't be able to leave this place because we will surely catch you!" Isao said confidently. He didn't know what Theta was thinking, but he was sure that person wouldn't be able to run away from them again.
"Ahaha! You don't have to worry because I don't intend to run away. But you seem to have forgotten something important." Theta said mysteriously.
"What do you mean by that? I'm sure I haven't forgotten anything. Didn't you infiltrate the League of Heroes headquarters and steal the serum? If you want to create a chance to escape by confusing me, then you better forget about your plan. It won't work for me." Isao sneered.
"You are stupid! I stole the serum from your headquarters and some of the monsters you experimented on!" Theta laughed loudly in response to Isao.
"What!?" Isao, Kasumi, and Subaru were shocked after they heard that. But before they could reply to his words, Theta opened his mouth again.
"Do you want to ask where the monsters I stole from the League of Heroes are?" Theta grinned.
Isao and the others' faces sank as he understood the meaning of Theta's words.
"Where are you hiding those goblins!?" Isao roared to Theta.
"Hehe... I released it somewhere in Kyoto. You might hear the report once the monsters start attacking people." Theta was happy when he saw their reactions. Although his attempts to sow discord between them failed, he still had another plan.
"You!" Isao was angry, looking at him with bloodshot eyes. He wanted to charge toward Theta, but Subaru quickly stopped him.
"Isao! Please don't fall for his provocation. We must act calmly to catch him and search for the monsters he released in Kyoto." Subaru held Isao's hand and reminded him.
"Yeah, you're right." Isao nodded and then looked at the Realizers behind him.
"All the Realizers are ready to attack; our target is the Wyvern! We will take him down in one strike!" Isao gave orders to the Realizers of the League of Heroes, and the other two leaders followed suit.
"I will never let you attack me. Do you think that you have surrounded me? You are wrong! The real ones under siege are you guys!" Theta said, and the ground in the area suddenly shook.
Boooooooooooooooommmmmmmmmmmm!
Roaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaarrrrrrrrrrrrrrrrrrrrrrrrrrrrrr!
A monstrous creature suddenly appeared from Miyazu Bay. It was a five-headed monster and a subspecies of the dragon.
"It's a Hydra!" Isao and others said in unison and looked at the monster in disbelief.