In 2051, humans picked up a rock containing high-quality elements on Uranus, brought it back to Earth, and used this element in nuclear energy development. However, this element is possessed by ultra-high intelligence in the universe, and human science and technology cannot control this power at all. The crisis came when mankind arrogantly used this element to develop nuclear energy. Just when a nuclear explosion was about to occur, a long-haired "monster" fell from the sky and used the blocks on its tail to easily absorb the damage from the nuclear energy device. Then, it flew directly into space.
Just when people thought this was a friendly alien species and spent two years preparing to communicate with the "monsters". A space ship appears above the earth, and tens of thousands of "monsters" descend from the sky, killing humans. They use their claws to tear apart all Earth's defenses with ease. People only shed blood and died in the struggle, without the power to resist. However, scientist Chen Rong discovered during several detections that these "monsters" are very afraid of nuclear energy, and they handle nuclear energy with caution. Chen Rong planned to activate a nuclear explosion device that the "monster" had not discovered, thereby destroying the monster's base camp.
When Chen Rong took the activation key and secretly entered the monster base, he discovered the truth. The so-called "monsters" are just combat mechas, but the real invaders are bipedal creatures. They collect human genes and modify their own cells to cultivate species that are exactly the same as humans. In order to prove their identity, the invaders retained the blue skin gene and also modified the genes of useful human descendants, turning all people on earth into blue appearance.
The great elder of the alien species talked with Chen Rong. When he learned that humans would have been wiped out long ago, just because human culture left them a life, even all the invaders wanted to become humans on earth. After the great elder introduced all their plans and purposes, Chen Rong put down the activation key and committed suicide with a gun.
But the people on earth don't know.
Purpose: Environmental protection