Cannon Fodder Reborn: After Tampering with the Plot, I Became Invincible

As cannon fodder in the army of brave men, I witnessed the entire army die in battle. By pretending to be dead, I killed the Demon King with one blow while the brave man and the Demon King were dying together. But the demon king's roar before his death made my hair stand on end: "No! This is not the plot of the script!" When I opened my eyes again, I was reborn and was given twenty limited opportunities to be reborn. I relied on my past life memories to explore step by step, and finally discovered the truth of this world - everyone's fate has long been destined by the script. And I, the only variable, can become stronger as long as I tamper with the destined tragedy! After saving a passerby who should have died tragically, his power skyrocketed! Save your comrades who are destined to die, and your cultivation level will soar! Subvert the plot belonging to the brave, and the world will tremble! In this life, I am no longer a cannon fodder at the mercy of others. I want to break free from the shackles of fate and let this damn script completely collapse!