this looks rather interesting. I wonder if there were multiple "servers" that existed and what the time compression ratio was like, because it took 22 years before MC kills that instance's Baal in a solo run of the castle, yet the kid's dad returns in March with pleb gear. also, of the 120mil people isekai'd i find it hard to believe that only 400 would be quality at the point of the 24th rank demon lord. sure, maybe the beginning would be similar to SAO's situation where despair stops most of 'em, but the kid's dad's scrub gear shows that the difficulty wasn't like those settings where the weak get chipped away until it is only humanity's top elites that survive to defeat the final boss.