After a fierce exchange, Yu Kai seized his opportunity and plunged his sword like lightning into the chimpanzee's eye. The chimpanzee screamed and flailed its arms wildly, howling like a whirlwind, sending Yu Kai flying. Ignoring the pain, Yu Kai gritted his teeth and swiftly rushed forward, seizing the opportunity to plunge his sword into its throat, plunging most of the way in.

Finally, the huge mutant chimpanzee fell to the ground with a dull sound, and there was no movement anymore. There was dead silence all around.

Yu Kai gasped for air, slumped to the ground. His mech was tattered, covered in wounds and bloodstains. The surroundings were in shambles, scattered with ruins, as if after apocalyptic events. Niuniu quickly stepped forward to collect the mutation beads for him.

At this moment, the voice of Academician Chao Tian suddenly rang out throughout the city. Some of the voice came from the huge screen in the shopping mall, some from the radio in the abandoned car, and some spread from the loudspeakers on the billboards on the street.

"Yu Kai, this is Chao Tian. We need you to come back! The entire Earth is now shrouded in powerful mutant creatures. People can no longer work normally, the land is barren, factories have stopped production, and the problem of material shortages is becoming increasingly serious. We must quickly develop a vaccine to control mutations, otherwise the entire Earth will be in dire straits and humanity will lose its last chance of survival. Currently, countries around the world have tried every possible means and exhausted all their resources, but with little success. However, your and Niuniu's special situation gives the Gene Research Institute hope. They need your help, and humanity needs your help!"

At this moment, Niu Niu flew over holding the huge mutant bead, her eyes full of vigilance and resistance, "Brother! We won't go back. Bad guys are all bad guys!" Her voice was filled with anger and fear.

Just when Yu Kai was about to persuade her, he saw Niu Niu baring her sharp fangs and roaring angrily at the surroundings, as if she wanted to be an enemy of the whole world.

At this moment, Academician Fang's voice rang out urgently: "Yu Kai, Niuniu, listen to me. We are not bad people. Everything we do is to save the world and allow more people like you to live normal lives. Now the mutants are becoming more and more powerful. If we don't find a solution soon, everyone will face a catastrophe. Think about it, if the world really is destroyed, where can you escape to? Come back, let's work together, and we will definitely find a way to control mutations and give humanity a bright future."

As Yu Kai listened, a look of hesitation appeared on his face. He looked at the angry Niu Niu, then looked up in the direction where the voice came from, and his heart was in a fierce struggle.

Niuniu remained unmoved. She hugged the mutant bead tightly and shouted to the sky: "You are all liars! I won't believe you!"

Academician Fang continued, "Niuniu, child, I know you may have been hurt before, but please trust us this time. We will do our best to protect you, and we need your strength to fight this disaster together. Yu Kai, you are a responsible person. Can you bear to watch humanity go to extinction like this?"

Yu Kai took a deep breath and said to Niuniu, "Niuniu, maybe we should go back and listen to what they have to say. Maybe we can really do something for everyone."

Niuniu widened her eyes and looked at Yu Kai in disbelief: "Brother, are you going to leave me too?"

Yu Kai quickly explained: "No, Niuniu, I will never leave you. But this may be our chance to save the world."

At this time, Academician Fang's voice came again: "Yu Kai, Niuniu, we are waiting for you at the base. Trust us, we will not hurt you."