I Was Reborn and Became the Master in the Troubled Times, Killing Like Crazy

My name is Xia Tian, ​​and I am a senior high school student. In my last life, I kept fighting monsters and upgrading to protect my classmates, but in the end they teamed up to kill me. Having the system in this life, I will not be killed by them again when I am reborn. All the humiliation I suffered in the previous life will be returned to them a thousand times. In this world, there will be sudden changes in the world in two and a half months. Creatures in nature begin to mutate, and human beings' current technological methods are powerless to deal with them. But when mutant creatures appeared, some people with superpowers also appeared, and everyone had superpowers. What's even more amazing is that you can practice it. When everyone breathes in and out, little spots of light appear around their body. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.