Its going a little too fast right? MC comes from the future, he was also in the same region .... You will tell me that humanity (in this corner of the world, in this continent, in this region) managed to survive while at the same time not some days, only a month, MC finds monster evolved, then he finds minautors, then even more powerful aliens?
Normally that, humanity in a few days should not even know the existence of evolutionary object embedded in the zombies (who at the idea of swallowing ??? when there is a possible risk that it contaminates the person like rain, because as far as I know no one knows the consequences of the apocalypse)
So some may be lucky to know about the existence, but given the degree of scale of the apocalypse, they should not survive ... Only certain, lucky, would have died within 3 months...