Gao Meng, a former special soldier, was seriously injured while protecting his comrades during an extreme mission and lost his right arm. After waking up, he was equipped with a biochemical mechanical prosthetic "Guardian" secretly developed by the military. This prosthetic limb has incredible power, but its real secret lies in its ability to sense and absorb the "malice" of surrounding creatures and convert it into energy. The stronger the malice, the more terrifying the power of the prosthetic limb. However, this power is not free. Every time it is absorbed, it quietly erodes Gao Meng's mind and lures him towards the abyss of violence and paranoia. After being forced to retire, Gao Meng tried to return to his ordinary life, but his prosthetic limb's thirst for malice drew him into countless conflicts. He discovered that malicious sentiment was rising unnaturally around the world, as if an invisible hand was behind the scenes. Gao Meng realizes that his prosthetic limb may not be an accident, but part of a huge conspiracy - a mastermind behind the scenes who is trying to feed on the negative emotions of humans around the world to achieve his ultimate goal.
