Earth Cleansing

In 2030 AD, the world was shaken, and a crack visible to the naked eye appeared in the sky. Then it fell into silence, hanging quietly in the sky. Five years later, one night late at night, just as it had appeared, monsters flew out of the cracks one after another, leaving corpses everywhere, ringing the death knell of the world. This is the cleansing from the earth. Humanity has only two choices: either perish or kill all the monsters and become the master of the earth again in the ruins!