Global Mutation: My Body Is Infinitely Upgraded

For unknown reasons, animals around the world began to become extremely powerful. In order to avoid the invasion of these animals, the country established five underground shelters in each city. Xiao Chen traveled to this world and immediately had to face these monsters! Fortunately, he got the Cosmic Brain System, which allows his body to be infinitely upgraded! What is the cause of the mutation? Can Xiao Chen solve these mysteries? This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.