Beginning of the Universe

Apocalypse started, portals opened, monsters came from within. Our MC got swallowed and reaches the other side of the portal where his only motive is to survive in the world filled with monsters. And there is more to the world it seems from the outside. Can he survive? Can he escape this world? Getting trapped was only the start of his story. Join his adventure full of up and downs and becoming a LEGEND. My first work. And the start is very slow please tolerate it and give it a go.